If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Rate Thread | Display Modes |
#1
|
|||
|
|||
SSD and computer casing.
My computer case is of Aluminium and earthed to a domestic copper
water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. |
Ads |
#2
|
|||
|
|||
SSD and computer casing.
On Sun, 15 Apr 2018 09:51:56 +1000, Peter Jason wrote:
My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. It shouldn't be a problem if the SSD has a case around it. I wouldn't let a MSATA type drive flop around in there. Speaking of flopping, I'm using an old Lenovo M72 It has room for one 3.5" drive and I've one 2.5" SSD and one 2.5" disk drive. There wasn't enough room in there to mount the SSD to the bracket and still get the connectors to mate properly, so it is loose and works fine (my desktop doesn't get moved often or treated harshly). I've also plugged in plenty of drives that weren't screwed down to see what was on them without the cases being grounded. Plenty of laptops work without any earth ground on the power supply, but with an internal supply, a grounded case will protect you from a shock if water gets in it or a wire shorts to the case. |
#3
|
|||
|
|||
SSD and computer casing.
On Sun, 15 Apr 2018 09:51:56 +1000, Peter Jason wrote:
My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. If you have the space to install a 3.5" storage device then you might consider a conversion tray which provides for you to securely install a 2.5" drive to a 3.5" bay. Check your local PC parts store. |
#4
|
|||
|
|||
SSD and computer casing.
Peter Jason wrote:
My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul |
#5
|
|||
|
|||
SSD and computer casing.
On Sat, 14 Apr 2018 22:25:50 -0400, Paul
wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul Thanks Paul. I have put my SSDs in plastic sleeves, and rested this combination on cardboard. I thought this might be the cause of my computer restarts. Also I have disabled all "fast startups" via the registry. |
#6
|
|||
|
|||
SSD and computer casing.
Peter Jason wrote:
On Sat, 14 Apr 2018 22:25:50 -0400, Paul wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul Thanks Paul. I have put my SSDs in plastic sleeves, and rested this combination on cardboard. I thought this might be the cause of my computer restarts. Also I have disabled all "fast startups" via the registry. I wouldn't entirely insulate the thing. Some SSDs have high peak power usage (SandForce compression), and they get a little warm. Put a cardboard underneath if you like. Leave at least one metal surface for cooling. In this review, you can see (and it's mentioned in the text), that thermal pads were used on all the NAND chips. That means both metal surfaces are used for their slight cooling advantage. http://www.thessdreview.com/our-revi...-review-512gb/ Paul |
#7
|
|||
|
|||
SSD and computer casing.
On Sun, 15 Apr 2018 09:51:56 +1000, Peter Jason wrote:
My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs Go to Amazon.com and buy an SSD tray or mounting bracket for each SSD you have. They are only a few dollars each and will let you install the SSDs in 3.5" drive bays. |
#8
|
|||
|
|||
SSD and computer casing.
On Sun, 15 Apr 2018 09:25:01 -0600, ken1943
wrote: Go to Amazon.com and buy an SSD tray or mounting bracket for each SSD you have. They are only a few dollars each and will let you install the SSDs in 3.5" drive bays. I wrapped one in bubble wrap and stuck in a 3.5 bay. Do they get hot? I don't know for sure, but if they do, what you did could start a fire. |
#9
|
|||
|
|||
SSD and computer casing.
"Paul" wrote in message news
Peter Jason wrote: On Sat, 14 Apr 2018 22:25:50 -0400, Paul wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul Thanks Paul. I have put my SSDs in plastic sleeves, and rested this combination on cardboard. I thought this might be the cause of my computer restarts. Also I have disabled all "fast startups" via the registry. I wouldn't entirely insulate the thing. Some SSDs have high peak power usage (SandForce compression), and they get a little warm. Put a cardboard underneath if you like. Leave at least one metal surface for cooling. In this review, you can see (and it's mentioned in the text), that thermal pads were used on all the NAND chips. That means both metal surfaces are used for their slight cooling advantage. http://www.thessdreview.com/our-revi...-review-512gb/ Paul Paul, Have no idea why you would expect the SSD to be isolated from case ground. Everything in the computer and the case itself is tied to the grid ground. Mount a motherboard and the mounting screws screw into the case as well as the screw heads tighten down on ground pads on the motherboard. SSD's are also grounded when placed in a mounting tray to case ground. As for the longer pins on power and data connectors, the pins that are designated as ground pins are longer to insure a ground connection is made before any data pins mate to prevent static discharges. This pin design also accommodates "hot swap" capable devices such as hard drives and SSD's. While it's always good practice to use measures to prevent ESD when mounting a device such as a SSD, do not isolate it from the mounting mechanisms such as placing an insulator between it and a metal case. Depending on the SSD (some cases are plastic), the metal case is the heat sink as shown in the link you included in your post. Please note that the logic board is held in-place by a screw in the back that fastens to the SSD case and tightens against a ground pad on the SSD logic board. -- Bob S. |
#10
|
|||
|
|||
SSD and computer casing.
On 15/04/2018 00:51, Peter Jason wrote:
the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs Why buy a 2.5 inch drives when you don't have the facility to use them? Do I sense some mental problems here? Why not plan in advance when buying something!!. There is no point in buying something just because it is new and your neighbour has got one. It's plain silly. 3.5 inch drives are much cheaper because they are produced in bulk and the users change their drives more frequently than on their laptops. 2.5 were made mainly for laptops but these days desktops and laptops are almost identical but desktops still have more accommodation for different devices. /--- This email has been checked for viruses by Windows Defender software. //https://www.microsoft.com/en-gb/windows/comprehensive-security/ -- With over 600 million devices now running Windows 10, customer satisfaction is higher than any previous version of windows. |
#11
|
|||
|
|||
SSD and computer casing.
On 4/15/2018 11:52 AM, Bob_S wrote:
"Paul"Â* wrote in message news Peter Jason wrote: On Sat, 14 Apr 2018 22:25:50 -0400, Paul wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium.Â* Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface.Â*Â* Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. Â*Â*Â* GNDÂ*Â*Â*Â*Â*Â*Â*Â* GNDÂ*Â*Â*Â*Â*Â*Â*Â* GNDÂ*Â*Â* === logic ground pins are longer Â*Â*Â*Â*Â*Â*Â* tx+ tx-Â*Â*Â*Â* rx+ rx-Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* on the SSD connector. The data Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* pins on the 7 pin data are Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* recessed. Check with the ohmmeter, Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* between GND and chassis, and you'll Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter Â*Â* what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Â*Â* Just like you would not touch any "hot" Molex pins, Â*Â* to the computer case metal posts. The motherboard has a hard Â*Â* short to the chassis, through the standoffs. Most everything Â*Â* in the computer, has a hard ground. The only poorly designed Â*Â* feature, is "plastic fascia" on the front of the computer, Â*Â* around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your Â*Â* SSD by the aluminum casing. Keep unused SSDs in an ESD bag, Â*Â* scuff across the carpet if you must, pick up the Â*Â* SSD by the ESD bag, touch the ESD bag plastic on Â*Â* the inside of the bag, to bring yourself and the bag contents Â*Â* to the same potential. With your other hand, touch Â*Â* the computer chassis. Now, everything is "drained" to Â*Â* the same electrostatic potential, you can remove the Â*Â* SSD from the ESD bag, and connect it to SATA power Â*Â* and SATA data. Â*Â* By using the series resistance of the ESD bag, to limit Â*Â* ESD current flow, you're *safely* bringing the SSD up Â*Â* to the same electrostatic potential as the thing you Â*Â* wish to connect it to. Note: I just changed my handling procedure! as a result Â*Â*Â*Â*Â* of this ohmmeter measurement. I'd assumed SSD chassis Â*Â*Â*Â*Â* were drain connected, not "hard" connected. Now I Â*Â*Â*Â*Â* will have to start using ESD bags for them, just as Â*Â*Â*Â*Â* I do for hard drives. Â*Â* Paul Thanks Paul.Â* I have put my SSDs in plastic sleeves, and rested this combination on cardboard.Â*Â* I thought this might be the cause of my computer restarts.Â*Â* Also I have disabled all "fast startups" via the registry. I wouldn't entirely insulate the thing. Some SSDs have high peak power usage (SandForce compression), and they get a little warm. Put a cardboard underneath if you like. Leave at least one metal surface for cooling. In this review, you can see (and it's mentioned in the text), that thermal pads were used on all the NAND chips. That means both metal surfaces are used for their slight cooling advantage. http://www.thessdreview.com/our-revi...-review-512gb/ Â*Â* Paul Paul, Have no idea why you would expect the SSD to be isolated from case ground. Everything in the computer and the case itself is tied to the grid ground. Mount a motherboard and the mounting screws screw into the case as well as the screw heads tighten down on ground pads on the motherboard.Â* SSD's are also grounded when placed in a mounting tray to case ground. As for the longer pins on power and data connectors, the pins that are designated as ground pins are longer to insure a ground connection is made before any data pins mate to prevent static discharges.Â* This pin design also accommodates "hot swap" capable devices such as hard drives and SSD's. While it's always good practice to use measures to prevent ESD when mounting a device such as a SSD, do not isolate it from the mounting mechanisms such as placing an insulator between it and a metal case. Depending on the SSD (some cases are plastic), the metal case is the heat sink as shown in the link you included in your post.Â* Please note that the logic board is held in-place by a screw in the back that fastens to the SSD case and tightens against a ground pad on the SSD logic board. Had no idea the ground pins were longer, thanks Data, er, Paul. |
#12
|
|||
|
|||
SSD and computer casing.
Mike S wrote:
On 4/15/2018 11:52 AM, Bob_S wrote: "Paul" wrote in message news Peter Jason wrote: On Sat, 14 Apr 2018 22:25:50 -0400, Paul wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul Thanks Paul. I have put my SSDs in plastic sleeves, and rested this combination on cardboard. I thought this might be the cause of my computer restarts. Also I have disabled all "fast startups" via the registry. I wouldn't entirely insulate the thing. Some SSDs have high peak power usage (SandForce compression), and they get a little warm. Put a cardboard underneath if you like. Leave at least one metal surface for cooling. In this review, you can see (and it's mentioned in the text), that thermal pads were used on all the NAND chips. That means both metal surfaces are used for their slight cooling advantage. http://www.thessdreview.com/our-revi...-review-512gb/ Paul Paul, Have no idea why you would expect the SSD to be isolated from case ground. Everything in the computer and the case itself is tied to the grid ground. Mount a motherboard and the mounting screws screw into the case as well as the screw heads tighten down on ground pads on the motherboard. SSD's are also grounded when placed in a mounting tray to case ground. As for the longer pins on power and data connectors, the pins that are designated as ground pins are longer to insure a ground connection is made before any data pins mate to prevent static discharges. This pin design also accommodates "hot swap" capable devices such as hard drives and SSD's. While it's always good practice to use measures to prevent ESD when mounting a device such as a SSD, do not isolate it from the mounting mechanisms such as placing an insulator between it and a metal case. Depending on the SSD (some cases are plastic), the metal case is the heat sink as shown in the link you included in your post. Please note that the logic board is held in-place by a screw in the back that fastens to the SSD case and tightens against a ground pad on the SSD logic board. Had no idea the ground pins were longer, thanks Data, er, Paul. Advanced ground prevents ESD or DC potential problems on tx+,tx-,rx+,rx- . Some connector systems use three lengths of pins, or even resort to power bugs, to sequence which pins touch first, second, third on an interface. They've done some complicated ones. Paul |
#13
|
|||
|
|||
SSD and computer casing.
Bob_S wrote:
"Paul" wrote in message news Peter Jason wrote: On Sat, 14 Apr 2018 22:25:50 -0400, Paul wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul Thanks Paul. I have put my SSDs in plastic sleeves, and rested this combination on cardboard. I thought this might be the cause of my computer restarts. Also I have disabled all "fast startups" via the registry. I wouldn't entirely insulate the thing. Some SSDs have high peak power usage (SandForce compression), and they get a little warm. Put a cardboard underneath if you like. Leave at least one metal surface for cooling. In this review, you can see (and it's mentioned in the text), that thermal pads were used on all the NAND chips. That means both metal surfaces are used for their slight cooling advantage. http://www.thessdreview.com/our-revi...-review-512gb/ Paul Paul, Have no idea why you would expect the SSD to be isolated from case ground. Everything in the computer and the case itself is tied to the grid ground. Mount a motherboard and the mounting screws screw into the case as well as the screw heads tighten down on ground pads on the motherboard. SSD's are also grounded when placed in a mounting tray to case ground. As for the longer pins on power and data connectors, the pins that are designated as ground pins are longer to insure a ground connection is made before any data pins mate to prevent static discharges. This pin design also accommodates "hot swap" capable devices such as hard drives and SSD's. While it's always good practice to use measures to prevent ESD when mounting a device such as a SSD, do not isolate it from the mounting mechanisms such as placing an insulator between it and a metal case. Depending on the SSD (some cases are plastic), the metal case is the heat sink as shown in the link you included in your post. Please note that the logic board is held in-place by a screw in the back that fastens to the SSD case and tightens against a ground pad on the SSD logic board. There are two ground philosophies for protecting assemblies from ESD. Neither was followed in this case. Paul |
#14
|
|||
|
|||
SSD and computer casing.
ken1943 wrote:
On Sun, 15 Apr 2018 08:32:03 -0700, Ken Blake wrote: On Sun, 15 Apr 2018 09:25:01 -0600, ken1943 wrote: Go to Amazon.com and buy an SSD tray or mounting bracket for each SSD you have. They are only a few dollars each and will let you install the SSDs in 3.5" drive bays. I wrapped one in bubble wrap and stuck in a 3.5 bay. Do they get hot? I don't know for sure, but if they do, what you did could start a fire. They run cool. Check specs. on one, they only draw under 2-4 watts for the size I use. Probably depends on how many chips/capacity one has. For the record, what's been "printed on the tin" of SSDs is just plain wrong. There is at least one web site, which has done measurements on a variety of models, which gives more realistic numbers. The site would open a box that said "200mW" on the outside, and find a healthy 2-3W draw instead, during sustained write. What's wrong with the "printed on the tin" value, is some marketing bunny decided to print the "devsleep" or other pointless numbers on the outside of the box. Like some badge of honor. When in fact, we want the "continuous read" or "continuous write" value, or high power state values, to decide how to handle the devices in various situations. The 2-4 watt value is a good estimate, first of all. There are some Sandforce ones up around 7 watts. That power number would not be sustained forever, but on a sustained write, it might be. The power might be coming from the data compression solution those controllers use. The ability to attempt to compress a full-rate stream, is pretty damn impressive. It's gotta use some power. One reason for needing to know the SSD peak power, is when the SSD is on a USB conversion cable (tether). This is why I measured the power on my SSDs and they all seem to be compatible with USB2 ports, if I use a converter. A USB2 port is good for 2.5W long term, 5W short term, and so a 7W SSD being "cloned over" on an SSD port, has the possibility of opening the Polyfuse on the motherboard, in mid-transfer. A second reason for needing a decent high-power-state value, is for laptops. Where the laptop bay is an "insulating" design, and from previous experience, only 5400 RPM drives "survived" in the completely-uncooled bay. A Kingston (Sandforce) drive might not be the best choice for such an application. Once an SSD is inside a desktop, there's no power engineering to do in there. If you're not cloning on a tether, but just cabling to the internal SATA cables, you'll be fine no matter what it is. Leave one exposed surface, so the small amount of heat can escape. Like, don't build a styrofoam box for it. There are some PCI Express ones that draw 15W. Again, not an issue, as they're open on both sides. And if the controller on those is a hot spot, it'll have a heatsink. Paul |
#15
|
|||
|
|||
SSD and computer casing.
"Paul" wrote in message news
Bob_S wrote: "Paul" wrote in message news Peter Jason wrote: On Sat, 14 Apr 2018 22:25:50 -0400, Paul wrote: Peter Jason wrote: My computer case is of Aluminium and earthed to a domestic copper water pipe. , the casing of the Samsungs SSDs seem to be anodized aluminium. Since my computer case is old it has no provision for 2.5" SSDs I have them resting on an aluminium surface. Is this a problem? I assume the SSDs have internal insulation. I just measured a couple SSDs here, and son of a bitch, there's a hard connection between SSD casing and logic ground! That's not supposed to be good for ESD handling. I was expecting to find a 1 megohm connection between aluminum SSD casing and the logic ground on the SSD. But it's a hard short. ******* The chassis of your computer case, runs at logic ground potential. The casing of your SSD, runs at logic ground potential. This means you can safely rest the SSD on the bottom of the computer case, without any "thru" current flowing. Just don't touch a 3.3V, 5V, or 12V pin from some Molex connector, to the chassis of the SSD. Since it's a hard ground, we can't be carelessly resting a Molex power pin in contact (somehow) with the chassis. While the pins on Molex are flush or slightly recessed, there might be some conceivable way for something to touch. And my finding a hard ground on the SSD chassis, is not a good thing. I'll be extra careful in future, to keep Molex away from it. I was really expecting to find a 1Megohm (high resistance) drain between shiny aluminum SSD casing and the logic ground next to the data pins of the SSD. GND GND GND === logic ground pins are longer tx+ tx- rx+ rx- on the SSD connector. The data pins on the 7 pin data are recessed. Check with the ohmmeter, between GND and chassis, and you'll see the hard short I measured. Summary: 1) Safe to rest SSD on bottom of computer case, no matter what the casing is made of. 2) Don't touch any "hot" Molex pins, to the SSD housing. Just like you would not touch any "hot" Molex pins, to the computer case metal posts. The motherboard has a hard short to the chassis, through the standoffs. Most everything in the computer, has a hard ground. The only poorly designed feature, is "plastic fascia" on the front of the computer, around front USB ports, which is a poor way to handle ESD issues. 3) Don't scuff across the carpet and pick up your SSD by the aluminum casing. Keep unused SSDs in an ESD bag, scuff across the carpet if you must, pick up the SSD by the ESD bag, touch the ESD bag plastic on the inside of the bag, to bring yourself and the bag contents to the same potential. With your other hand, touch the computer chassis. Now, everything is "drained" to the same electrostatic potential, you can remove the SSD from the ESD bag, and connect it to SATA power and SATA data. By using the series resistance of the ESD bag, to limit ESD current flow, you're *safely* bringing the SSD up to the same electrostatic potential as the thing you wish to connect it to. Note: I just changed my handling procedure! as a result of this ohmmeter measurement. I'd assumed SSD chassis were drain connected, not "hard" connected. Now I will have to start using ESD bags for them, just as I do for hard drives. Paul Thanks Paul. I have put my SSDs in plastic sleeves, and rested this combination on cardboard. I thought this might be the cause of my computer restarts. Also I have disabled all "fast startups" via the registry. I wouldn't entirely insulate the thing. Some SSDs have high peak power usage (SandForce compression), and they get a little warm. Put a cardboard underneath if you like. Leave at least one metal surface for cooling. In this review, you can see (and it's mentioned in the text), that thermal pads were used on all the NAND chips. That means both metal surfaces are used for their slight cooling advantage. http://www.thessdreview.com/our-revi...-review-512gb/ Paul Paul, Have no idea why you would expect the SSD to be isolated from case ground. Everything in the computer and the case itself is tied to the grid ground. Mount a motherboard and the mounting screws screw into the case as well as the screw heads tighten down on ground pads on the motherboard. SSD's are also grounded when placed in a mounting tray to case ground. As for the longer pins on power and data connectors, the pins that are designated as ground pins are longer to insure a ground connection is made before any data pins mate to prevent static discharges. This pin design also accommodates "hot swap" capable devices such as hard drives and SSD's. While it's always good practice to use measures to prevent ESD when mounting a device such as a SSD, do not isolate it from the mounting mechanisms such as placing an insulator between it and a metal case. Depending on the SSD (some cases are plastic), the metal case is the heat sink as shown in the link you included in your post. Please note that the logic board is held in-place by a screw in the back that fastens to the SSD case and tightens against a ground pad on the SSD logic board. There are two ground philosophies for protecting assemblies from ESD. Neither was followed in this case. Paul Paul, Not sure I follow your logic on this. The OP said he had his case grounded to a copper pipe. What wasn't stated is how his power supply is grounded or if it was even plugged in. In the US, the 3rd lug on a plug is the green (safety) ground and in a typical home wiring setup, the white wire and green are tied to a single bus bar in the distribution panel so as to prevent ground loops / current loops. So while his setup using a ground from the case to a copper water pipe could potentially create a ground loop if there were other wiring problems, it still is ground as long as there's no interruption to earth ground in that copper pipe and in his wiring and would dissipate any ESD charge. Potential for ESD would be from him picking up the SSD and then plugging it in before he touched the case (grounding himself) and creating a arc between his hand holding the SSD and getting the data or power connectors close enough so the static potential went from him to the ground pins on the cable or the case. That’s' why the manufactures include warnings about using ground straps and/or touching the case before working on it. What people don't realize is that usually, they unplug the power cord from the wall or the power supply and that’s when their case is no longer grounded. But in the OP's situation, he had an additional ground to a water pipe. That may or may not be a good situation depending on his house wiring and I've never seen a power supply plug without a polarized plug. Now if the wall socket (old house wiring) does not have a safety ground, then his water pipe ground is a good idea. I've worked at radar sites and on some of the largest computer installations in the world and worked worked with power engineers that specialize in how "all things" need to be grounded and why. It is a complicated field of study and ESD can create havoc on computer components when you have thousands of volts jumping between you and the computer. So I'm not trying to argue with you but saying "Neither was followed in this case" didn't make sense to me. Perhaps you could expand on the "Neither" a bit. I'm not sure if you are referring to the OP or to your own situation. If it's your own, then I'll shut up and sit down cause I don't know what or how you were doing your measurements. -- Bob S. |
Thread Tools | |
Display Modes | Rate This Thread |
|
|