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#16
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SCR attack
On Mon, 2 Dec 2019 19:55:57 -0600, VanguardLH wrote:
Some users think a black (blank) screensaver consumes less power than an all-white screensaver. They don't know how LCDs work. All all-black screensaver consumes an itty bitty more power than an all-white screensaver, because of the lack of having to apply power to twist the polarizer to block the light from the LED. The backlamp is always on. Whether you see it for a pixel depends on whether or not the polarizer is energized. An energized polarizer consumes more power than a relaxed polarizer. I did not know that. What about when the computer sleeps? I'm wondering specifically about laptops. As far as the laptop screen is concerned, is computer sleep equivalent to a black screensaver, or does the laptop screen actually see less power (or no power) when the computer is asleep? -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://BrownMath.com/ http://OakRoadSystems.com/ Shikata ga nai... |
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#17
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SCR attack (and display lighting by ambient)
In message , Stan Brown
writes: On Mon, 2 Dec 2019 19:55:57 -0600, VanguardLH wrote: Some users think a black (blank) screensaver consumes less power than an all-white screensaver. They don't know how LCDs work. All all-black screensaver consumes an itty bitty more power than an all-white screensaver, because of the lack of having to apply power to twist the polarizer to block the light from the LED. The backlamp is always on. Whether you see it for a pixel depends on whether or not the polarizer is energized. An energized polarizer consumes more power than a relaxed polarizer. I did not know that. What about when the computer sleeps? I'm wondering specifically about laptops. As far as the laptop screen is concerned, is computer sleep equivalent to a black screensaver, or does the laptop screen actually see less power (or no power) when the computer is asleep? Nearly always (I think always), when a laptop goes into any of the low-power modes, the display backlight is turned off, which is the largest component of the power consumption of the display. I _suspect_ the video output turns off too, but that's very much a second or third order component compared to the backlight. (I guess you could find out by connecting an external monitor and see whether _that_ goes off - though the laptop may treat external displays differently.) Incidentally, I've often wondered why no laptop uses ambient light. I remember many years ago, where I worked had a Sony camera, whose back display had a conventional backlight, but also a diffuser that continued to a strip along the top: in sunny conditions, you could turn the backlight off, but the display was perfectly visible by the daylight being collected by this diffuser. (You may say it was only quite a small display, but for the time it was quite large: the camera had a floppy drive in it, and the display was about that size. Besides, a laptop screen could have several such strips along the back, say two inches apart.) -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf I don't like that word [atheist]; it implies that there's a god not to believe in - Eric Idle, quoted in RT 2016/12/10-16 |
#18
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SCR attack
In article , Stan Brown
wrote: What about when the computer sleeps? I'm wondering specifically about laptops. As far as the laptop screen is concerned, is computer sleep equivalent to a black screensaver, or does the laptop screen actually see less power (or no power) when the computer is asleep? sleep is effectively the same as off, except memory is maintained so it can instantly wake. sometimes memory is written to the hard drive and powered down, which takes slightly longer. |
#19
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SCR attack
Stan Brown wrote:
On Mon, 2 Dec 2019 19:55:57 -0600, VanguardLH wrote: Some users think a black (blank) screensaver consumes less power than an all-white screensaver. They don't know how LCDs work. All all-black screensaver consumes an itty bitty more power than an all-white screensaver, because of the lack of having to apply power to twist the polarizer to block the light from the LED. The backlamp is always on. Whether you see it for a pixel depends on whether or not the polarizer is energized. An energized polarizer consumes more power than a relaxed polarizer. I did not know that. What about when the computer sleeps? I'm wondering specifically about laptops. As far as the laptop screen is concerned, is computer sleep equivalent to a black screensaver, or does the laptop screen actually see less power (or no power) when the computer is asleep? There has to be a means to turn off the backlight! Sleep power should be limited to providing roughly 1 watt per DIMM on a DDR3 or DDR4 machine. So when a computer sleeps, the session is stored in DRAM, the DRAM still receives power and a clock signal, and the DRAM is issued an "autorefresh" command before parking. An address counter runs inside the DIMM, to make sure each location is visited at a regular rate, before the charge on the floating gate, drains away. If you want to get hours and hours out of the laptop in S3 sleep, all other vampire loads have to be removed. Then it's a matter of dividing the watt-hours of the battery pack, by that few watts of load from the installed DRAM. When the computer is running, two DIMMs sitting on the same channel, one DIMM is in autorefresh (is drawing 1 watt), the second DIMM executes higher power cycles (read or write). Maybe the DIMM draws 3 watts for a higher power cycle. And the DIMM doesn't have to do back-to-back higher power cycles either, so that the average power is only a little higher than autorefresh. If you install DIMMs in dual channel mode, you pay extra power for powering up the second channel, plus you have the opportunity to leave the DIMM running in the higher power state. While dual channel is important for giving "snappy integrated graphics performance", you are actually paying a price for that in terms of battery life. The CPU on the other hand, when the computer is in S0, is really hammering the battery, and these distinctions might be more important on a tablet with a 10 hour battery life. A tablet with a 10 hour battery life, might be using a processor with a 2W SDP. And now, the punishment the DIMMs provide, matters. A good design will then only use a single channel (or in the case of the cheapest Intel products, a "half-channel" 32 bits wide, done with soldered-down RAM chips). In S3, almost all primary power is removed. Only a little sustaining power is provided, and that still requires a switching converter. The backlight has to go off, since the backlight could use as much power or more, than the DIMMs. In S0 (what I think of as a "mostly useless" state), they can implement that however they want. Yes, the screen can go black, but they have options as to how it can assume a black color. You can turn all the pixels black, or, you can set the PWM on the backlight to zero and cause the inverter to stop running. The power to run a LED backlight, has to come from somewhere, will use a switching converter, and the backlight also needs modulation capability. If it uses a PWM signal, you can have the PWM response curve pass through (0,0) and get the desired lower power feature for free. The PWM, when at a DC level, can be used to blank the display by removing the light. As for LCD displays, most of the displays we use are transmission displays. But there are monochrome ones which are reflective, and there are a few which are... transreflective, and operate both modes, and those are excellent in sunlight. https://en.wikipedia.org/wiki/Transf...rystal_display Paul |
#20
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SCR attack
"JJ" wrote
| I'd suggest not associate it with `txtfile`, since by default, it will be | opened using Notepad, and Notepad can be very slow when loading a binary | file. True, but I don't mind. Notepad is safe and having it try to open the file would ensure that I become aware something's amiss. It's doubtful that I'd ever even make the mistake. The TXT association is just insurance in case I'm not paying attention. And once Notepad did get it open I'd be able to see that it was EXE. I've often wondered why Notepad gets so stumped. It could just open it as ANSI. Maybe it goes in circles trying to figure out what encoding it is? That would make sense. It seems to me that the older, non-unicode-aware Notepad had no trouble opening an EXE as text. |
#21
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SCR attack
On 03.12.19 15:35, Mayayana wrote:
"JJ" wrote | I'd suggest not associate it with `txtfile`, since by default, it will be | opened using Notepad, and Notepad can be very slow when loading a binary | file. True, but I don't mind. Notepad is safe and having it try to open the file would ensure that I become aware something's amiss. It's doubtful that I'd ever even make the mistake. The TXT association is just insurance in case I'm not paying attention. And once Notepad did get it open I'd be able to see that it was EXE. I've often wondered why Notepad gets so stumped. It could just open it as ANSI. Maybe it goes in circles trying to figure out what encoding it is? That would make sense. It seems to me that the older, non-unicode-aware Notepad had no trouble opening an EXE as text. Install notepad++, that opens anything fast, and knows about a lot of formats. |
#22
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SCR attack (and display lighting by ambient)
On Tue, 3 Dec 2019 12:01:40 +0000, J. P. Gilliver (John) wrote:
In message , Stan Brown writes: [quoted text muted] equivalent to a black screensaver, or does the laptop screen actually see less power (or no power) when the computer is asleep? Nearly always (I think always), when a laptop goes into any of the low-power modes, the display backlight is turned off, which is the largest component of the power consumption of the display. I _suspect_ the video output turns off too, but that's very much a second or third order component compared to the backlight. (I guess you could find out by connecting an external monitor and see whether _that_ goes off - though the laptop may treat external displays differently.) Thanks, John, and thanks also to Paul. -- Stan Brown, Oak Road Systems, Tompkins County, New York, USA http://BrownMath.com/ http://OakRoadSystems.com/ Shikata ga nai... |
#23
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SCR attack
"Mayayana" on Mon, 2 Dec 2019 21:49:05 -0500
typed in alt.windows7.general the following: "VanguardLH" wrote | How many users lock their computer before leaving it powered? A | screensaver can be configured to lock the workstation after an idle | timeout. News to me. I've never worked in an office or needed a computer anywhere but home. If I'm using it it's on. If I take a break it's on standby. Otherwise it's off. In none of those situations would a screensaver be relevant. I've also never had a computer configured to go into standby or activate a screensaver after a period of inactivity. I never used a screensaver with a CRT, either, but I didn't leave it turned on. There was no reason to do so. But I can see how it might be different if you're not at home. I have a password on my account. The only human in the place was me. "Just something to keep the cat from going online." -- pyotr filipivich Next month's Panel: Graft - Boon or blessing? |
#24
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SCR attack
On 12/2/19 2:59 PM, Mayayana wrote:
Just a note about a current attack. I just got an email with an attached .SCR. No message. Screensaver! I'd forgotten those existed. I changed HKCR\.scr default value to "txtfile" and deleted HKCR\scrfile\ I don't know of any reason for screensavers to still exist. I certainly don't use them. AFAIK, LCD monitors don't have the problem a screen saver is meant to solve. If you want to save power there's better ways than a program that demands additional CPU time. -- 22 days until the winter celebration (Wed, Dec 25, 2019 12:00:00 AM for 1 day). Mark Lloyd http://notstupid.us/ "We cannot hope for a society in which formal organized religion dies out. But we can stop behaving as if it was worthy of our collective respect." [A. N. Wilson, "Against Religion"] |
#25
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SCR attack
"pyotr filipivich" wrote
| I have a password on my account. The only human in the place was | me. "Just something to keep the cat from going online." That's why I no longer have a cat. They have a way of racking up charges on gaming sites. I actually have a BIOS password, so someone can't start the computer when I'm not here. But it's not really critical. I don't bank or shop online. There are no credit card or account numbers to find. But I guess that's one way I do things differently from most people. I not only don't bank online but I also don't leave my computer on when I'm out. It seems like most people rarely if ever turn off their computer. That seems crazy to me. I shut it off every night. The 30 second boot doesn't bother me. |
#26
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SCR attack
"Sjouke Burry" wrote
| Install notepad++, that opens anything fast, and knows about a lot | of formats. Yes, I have that. A very solid piece of software. But I only use it rarely, for gigantic files. It's overkill for what Notepad can do and it's not nearly specialized enough for any kind of coding I do. The whole thing is really just a simple wrapper for the Scintilla RichEdit control, which is a solid but general purpose edit window. Like so many editors, they claim support for dozens of programming languages. Like so many editors, by being a jack of all codes they're a master of none. So N++ has become my program for reading the occasional 100 MB text file. |
#27
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SCR attack
VanguardLH wrote:
VanguardLH wrote: Just because you have done so, ... Oops. Should be "Just becasue you have not done so, ..." ^^^ ARGH!!!! ^^^^^^^___ because Damn fingers won't do what I tell them to do. |
#28
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SCR attack
Mayayana wrote:
"pyotr filipivich" wrote | I have a password on my account. The only human in the place was | me. "Just something to keep the cat from going online." That's why I no longer have a cat. They have a way of racking up charges on gaming sites. I actually have a BIOS password, so someone can't start the computer when I'm not here. But it's not really critical. I don't bank or shop online. There are no credit card or account numbers to find. But I guess that's one way I do things differently from most people. I not only don't bank online but I also don't leave my computer on when I'm out. It seems like most people rarely if ever turn off their computer. That seems crazy to me. I shut it off every night. The 30 second boot doesn't bother me. It's a good idea to turn off Windows 10, because it has a bad habit of waking up whenever it feels like it, and doing God knows what. Paul |
#29
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SCR attack
On 12/3/2019 12:46 PM, Mayayana wrote:
"pyotr filipivich" wrote | I have a password on my account. The only human in the place was | me. "Just something to keep the cat from going online." That's why I no longer have a cat. They have a way of racking up charges on gaming sites. I actually have a BIOS password, so someone can't start the computer when I'm not here. But it's not really critical. I don't bank or shop online. There are no credit card or account numbers to find. But I guess that's one way I do things differently from most people. I not only don't bank online but I also don't leave my computer on when I'm out. It seems like most people rarely if ever turn off their computer. That seems crazy to me. I shut it off every night. The 30 second boot doesn't bother me. I agree the safest computer is one that is not on. I turn my computers off when not in use. |
#30
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SCR attack
On 12/3/2019 5:38 PM, Paul wrote:
Mayayana wrote: "pyotr filipivich" wrote | I have a password on my account.Â* The only human in the place was | me.Â* "Just something to keep the cat from going online." Â*That's why I no longer have a cat. They have a way of racking up charges on gaming sites. I actually have a BIOS password, so someone can't start the computer when I'm not here. But it's not really critical. I don't bank or shop online. There are no credit card or account numbers to find. Â* But I guess that's one way I do things differently from most people. I not only don't bank online but I also don't leave my computer on when I'm out. It seems like most people rarely if ever turn off their computer. That seems crazy to me. I shut it off every night. The 30 second boot doesn't bother me. It's a good idea to turn off Windows 10, because it has a bad habit of waking up whenever it feels like it, and doing God knows what. Â*Â* Paul Putting the computer in the sleep mode is not the same as turning off the computer. To my knowledge there is no software that can activate the hard ware switch. |
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