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#16
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows(Dell Precision T7400, upgraded from Win 7 Home)
On 12/11/2018 12:33, NY wrote:
Having just upgraded it to Windows 10 Home 1803 which has a much higher max memory, I'm puzzled that Settings | System (and Control Panel | System) still reports "32 GB, 16 GB available". It could be that you have installed incompatible modules. Did you not bother to scan your machine BEFORE purchasing them? Crucial have a free scanner and you could have used it before buying anything. The scanner tells you what is the capacity on your machine and which brand is compatible with what you already have. Well, treat this as a lesson learned. Next time do a through research before taking out your credit card and using it just because you like spending time on the net. Why does your wife need all that RAM? Is she cleverer than you? -- With over 950 million devices now running Windows 10, customer satisfaction is higher than any previous version of windows. |
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#17
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows(Dell Precision T7400, upgraded from Win 7 Home)
NY wrote:
My wife is over the moon to have 36 GB. Not because she needs it but because she had bought it at great expense (the vendor charged almost the same for 2, 4 or 8 GB DIMMs so she got the biggest) and wanted to be able to make full use of them if she ever needed to run a memory-hungry app. You should be testing with memtest, and do at least one full pass. (There's a pass counter on the 640x480 screen.) http://memtest.org/ Downloads are half way down the web page. Various media formats are available, to suit machines with fewer storage options. I recommend memory testing, on average, about once a year, as part of preventive maintenance. That's not the only test you can run, but it does do a stuck-at test for you. Memory failures come in a couple types. Stuck-at faults are memory bits that can no longer be flipped. Transient faults (never the same address, twice) can be cause by bus noise issues. The FBDIMM isn't likely to have bus noise issues, but you can still have stuck bits on the memory chips themselves. Memtest also has a bandwidth display, which you can check to see if the value makes sense or not. For example, my quad channel system here, the measured bandwidth is only 25% of theoretical, which means the thing basically runs dual channel mode inside. Not a big deal, except in bar bets. Paul |
#18
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
NY wrote:
I'm not sure what the best advice is on page file strategy - hard-coded versus letting Windows manage it. Any comments, anyone? Should I reset it back to the default of "Allow..." and System Managed size? In the past, I set max and min pagefile size to the same 1.5*N value (where N is my physical system RAM). Having the same size for min and max meant the pagefile stayed the same size hence preventing further fragmentation of that file (after doing a defrag of it). Later with an 8GB system, it seemed ridiculous to have 12GB of fixed space allocated to a pagefile when there was 8GB of real RAM available. I knew that a zero-sized pagefile was incorrect because Windows wants some, some programs will error or fail if they request some but none is available, and some games error, fail to load, or crash without some (they want to offload their textures and objects into the pagefile which is on the disk because access is faster than doing file I/O on the disk). So I reduced the pagefile down to 4GB which seemed more than large enough. After a couple years and some updates to Windows and the programs, I started getting 7A BSODs at infrequent intervals. I did chkdsk /r, memtest, and a slew of other testing but nothing pointed at defective hardware and all testing was okay. I noticed the BSODs were after using Macrium Reflect free to perform a scheduled backup. The backup job completed okay and even the following verification of the backup. It was 5 minutes after the backup completed that a BSOD happened. I had also split the pagefile across 2 drives. If Windows sees part of the pagefile on a drive other than the one for the OS, it's supposed to get preference to using that other pagefile space. Now all the pagefile space is on the SSD. No splitting across drives and different types of drives (SSD for OS drive, HDD for data drive). I changed to system managed instead of trying to prevent fragmentation of the file with varying size (which different min-max values might do and system-managed would do) because fragmentation on an SSD doesn't cause the slowdown as it does for seeks on an HDD (the SSD still needs to get optimized occasionally to reduce fragments to reduce the meta data from all of them which could exceed the handling supported in the file table and why in Task Scheduler you'll find a scheduled defrag using MS's tool - so I reenabled that scheduled event). Although it says 12GB is reserved, that doesn't mean used. Windows, when pagefile is system managed, will vary the size of the pagefile as needed. When min is less than max, them is physically allocated on the drive but the remainder up to the max is only reserved for if and when it is needed. I had replaced an HDD with an SSD (and moved the old HDD to a data-only drive but with some pagefile space). To troubleshoot the BSODs, I moved all of the pagefile space to the SSD (the OS drive). With the changes in the pagefile (not split across different types of drives, well, not split at all and only on the OS drive, and using system managed sizing), I'll have to wait a month, or two, to see if the BSODs still occur 5 minutes after the backup & verify completes (which go to a different HDD but that's been chkdsk /r'd and tested, too). While my SSD is a lot smaller than my HDDs (256GB versus 1TB and 2TB), I was trying to save space by moving most of the pagefile off the SSD. That would also reduce the number of writes to the SSD since there is a max number of writes the SSD can handle. I'd rather have a stable PC than worry about more writes reducing the lifespan of the SSD. I have scheduled backups (daily-differential and weekly-full to the internal HDD, copied to a USB-attached HDD, and monthly-full to USB flash drives) to recover from hardware failure. I had originally split the pagefile because file I/O to the pagefile was parallel to writes to the OS drive, so paging would be faster. That wasn't true anymore when using the SSD where the other-drive pagefile would now be a lot slow than the part of the pagefile on the SSD. I had fixed the pagefile size to eliminate its fragmentation but that's not an issue when using an SSD. To sum up: the "16 GB available" was not a carry-over from Windows 7 that had been on the PC before. It was an inherent restriction that seems to affect Windows 10 (at least on this PC), that half the memory (no matter how much you have) seems to be "hidden" from Windows unless virtualization is turned on in the BIOS. My wife is over the moon to have 36 GB. Not because she needs it but because she had bought it at great expense (the vendor charged almost the same for 2, 4 or 8 GB DIMMs so she got the biggest) and wanted to be able to make full use of them if she ever needed to run a memory-hungry app. Most of the articles that I found on "hardware reserved" for memory pointed back to the BIOS. A new BIOS version was needed (so it matched the better capable hardware), devices had been allocated space (e.g., onboard video), and other settings that would reserve some memory making it unavailable to any OS. I had not thought that lack of virtualization support would cause allocation of memory the OS could not reach. Because BIOS had been mentioned often, in another reply I had suggested resetting the BIOS to either its default or optimized config. In my mind, the Xeon was an old processor, so I didn't think it supported VT-x virtualization. I haven't dealt with Xeon PCs for a very long time. https://en.wikipedia.org/wiki/List_o...icroprocessors shows the CoffeeLake family was released this year. https://www.intel.com/content/www/us...rocessors.html I looked up one of the Xeons (probably not yours) and it does list VT-x as supported. Since VT-x virtualization is supported by the Xeon processor, seems peculiar that it was disabled in the BIOS. You might want to reset the BIOS settings. After a reset, check the VT-x option is enabled (along with other BIOS settings, like AGP aperture size). You might also consider replacing the CMOS battery. Rarely are the BIOS settings read directly from the EEPROM chips where the BIOS settings are stored. Instead during boot the settings are read from the CMOS table where a copy of the BIOS settings are stored. If the battery goes weak or dead, the CMOS table can get corrupted. If the CMOS battery is over 5 years old, replace it. I noticed Device Manager (devmgmt.msc) can let you see what memory ranges have been reserved for hardware (in the BIOS). Load devmgmt.msc and go to the View - Resources by connection menu and expand the Memory node in the tree list. I haven't bothered to figure out which reserved memory ranges are included in the hardware reserved range. Maybe they all are. Some info he https://blogs.technet.microsoft.com/...ysical-memory/ |
#19
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows(Dell Precision T7400, upgraded from Win 7 Home)
NY wrote:
I hadn't noticed the max 4 GB DIMM in the Dell manual Though it's not unusual for limits that apply when a product is new (and are noted in the manual) to be altered over the years by firmware upgrades. |
#20
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
"?? Good Guy ??" wrote in message
news On 12/11/2018 12:33, NY wrote: Having just upgraded it to Windows 10 Home 1803 which has a much higher max memory, I'm puzzled that Settings | System (and Control Panel | System) still reports "32 GB, 16 GB available". It could be that you have installed incompatible modules. Did you not bother to scan your machine BEFORE purchasing them? Crucial have a free scanner and you could have used it before buying anything. The scanner tells you what is the capacity on your machine and which brand is compatible with what you already have. Well, treat this as a lesson learned. Next time do a through research before taking out your credit card and using it just because you like spending time on the net. Actually I *did* run the Crucial scanner on the PC. Crucial is the first place I go to for memory, just like Google is the first place for searching the web. Unfortunately they didn't sell any that was compatible with the PC - it's fairly old DDR2 memory. I had to try a smaller company which was the only one that advertised that type of memory for that particular model; I made sure they had a "guaranteed to work with this PC" clause so I could return it if there was a problem. The initial intention was to replace the existing RAM with new RAM, so I was looking for RAM DIMMs that would work with the PC but not necessarily with the existing DIMMs. It's only very recently that I've tried the two together - long after experiencing the original "32 GB (16 GB available)" problem. OK, Dell's original manual for the PC only lists DIMMs as large as 4 GB, and I bought 8 GB ones. I admit that I hadn't seen that restriction and that I was lucky the larger ones did work, though again it would be covered by the vendor's compatibility guarantee. I *did* do my research to the extent that I knew DIMMs needed to be added in groups of 4 with this motherboard. Anyway, the problem was not one of compatibility. It was due to a BIOS setting that needed to changed and which caused *any* amount of memory (whether 4 GB, 32 GB or 32+4=36 GB) to report 50% not being available to Windows 10: when I put the original 4 GB back temporarily, Win 10's Control Panel | System reported "4 GB (2GB available)"; it had not done this before the OS upgrade when I still had Win 7. |
#21
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows(Dell Precision T7400, upgraded from Win 7 Home)
Andy Burns wrote:
NY wrote: I hadn't noticed the max 4 GB DIMM in the Dell manual Though it's not unusual for limits that apply when a product is new (and are noted in the manual) to be altered over the years by firmware upgrades. In this case, it's hardly the normal constraints, because it's an FBDIMM interface. The AMB deals with the vagaries of the DRAM chip behind it (make a new AMB if different DRAM come along). The Northbridge on the motherboard, only has to feed the AMB an address. And whoever invented the FBDIMM interface, can select a sufficiently elevated size so that the package is more future proof. There really isn't a good excuse for a size limit, until they have to transmit an extra byte on the bus to carry it. Paul |
#22
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
Andy Burns wrote:
NY wrote: I hadn't noticed the max 4 GB DIMM in the Dell manual Though it's not unusual for limits that apply when a product is new (and are noted in the manual) to be altered over the years by firmware upgrades. That's why I mentioned Dell's data sheet and other reviews noting twice the maximum system RAM capacity might've been due to a BIOS update. From what I saw at Dell's site (which required using a search engine instead of Dell's search) was the latest BIOS version is A11 dated back in 2012. The hardware may outstrip the functions within a BIOS until a later update. The OP should look at the POST screen to see what he has. I would only do a BIOS update if I had a the computer on a UPS for a desktop or a fully charged battery for a laptop and make sure to first copy the old BIOS to archive in case the new BIOS has problems; however, a screwed up BIOS update can render the computer unusable resulting in not being able to burn in the old BIOS .bin file. However, the OP got all of his system RAM available by changing a BIOS setting: enabling the VT-x virtualization option. His Xeon processor probably supports the virtualization feature (the latest ones do but I don't know about his), so the question is why it got disabled requiring him to reenable it. His PC is probably over 5 years old and should have its CMOS battery replaced. For pre-builts, I usually schedule to replace the battery after 3 years because I won't know how old is the battery inside the pre-built or when the pre-built was assembled. Thereafter 5 years is a good time to replace the battery. On a desktop, it's an easy job. On a laptop or notebook, it's often a bitch. |
#23
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
VanguardLH wrote in :
NY wrote: I'm not sure what the best advice is on page file strategy - hard-coded versus letting Windows manage it. Any comments, anyone? Should I reset it back to the default of "Allow..." and System Managed size? My system has 24 GB of memory, and I have never seen it use more than 10 GB. In a case like this, how much is the page file actually used? I know windows stores some things there that one wouldn't normally think would be there, but other than that in a situation like mine will Windows page at all? |
#24
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
"VanguardLH" wrote in message
... His Xeon processor probably supports the virtualization feature (the latest ones do but I don't know about his), so the question is why it got disabled requiring him to reenable it. His PC is probably over 5 years old and should have its CMOS battery replaced. Thanks for the reminder about the CMOS battery. The PC is probably about 8-10 years old, so due for a new battery, especially as it wasn't used much for a few years so the CMOS will have been powered only by the battery with no periods of on-time when the PSU would have powered it. I don't *think* I've replaced the battery since the PC was new. I think I saw something either in the BIOS help text or the user manual which implied that the default state was for virtualization to be turned off. Would it cause problems for older operating systems if it was turned on? The PC came with XP (not sure whether it was home or pro). |
#25
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
Wolf K wrote:
Tim wrote: NY wrote: I'm not sure what the best advice is on page file strategy - hard-coded versus letting Windows manage it. Any comments, anyone? Should I reset it back to the default of "Allow..." and System Managed size? My system has 24 GB of memory, and I have never seen it use more than 10 GB. In a case like this, how much is the page file actually used? I know windows stores some things there that one wouldn't normally think would be there, but other than that in a situation like mine will Windows page at all? FWIW, I have 16GB RAM here, and the last time I checked the size of the page file it was zero. Win 8.1 Home 64 bit. You can use the Resource Monitor (filter on pagefile.sys) or SysInternals' Process Monitor (just file system events for pagefile.sys) to see if, when, and what is using the pagefile. You can use SysInternals' RAMmap to see what is allocated in system memory. Click on the Use column to sort by the type of usage and scroll all the way down until you reach memory chunks that are Paged Pool. https://docs.microsoft.com/en-us/win...y/memory-pools "The paged pool consists of virtual memory that can be paged in and out of the system." I'm at home so don't have a Win10 host to look at. On my home Win7 host, Task Manager's Performance tab show 387MB for Paged Pool (which is configured to a "system managed" /reserve/ of up to 13GB which is close to the recommended 1.5*N manual setting). That's now with my computer mostly idle except to compose this message while my NNTP client is running and with RAMmap and Chrome loaded. When I unloaded RAMmap and Chrome, the Paged Pool dropped to 384MB. I'd have to use Procmon or ResMon to see what happens when I run my games or during an image backup. The reserve is not the current allocation and 384MB of disk space for the pagefile is puny on a 256GB SSD and even more puny on a 1TB, or larger, HDD. https://support.microsoft.com/en-us/...it-versions-of You may not need a pagefile *if* you highly overexceeded the maximum memory requirement you will ever experience in your current setup. Of course, all that unused memory is wasted memory, especially if it is never used. Crash dumps record the contents of memory. 16GB and 24GB is a lot to read, and how do you read it without using it at the same time? Although we are discussing this in a Windows 10 newsgroup, there has yet been no mandate that this newsgroup discuss only 64-bit versions of Windows 10. There are 32-bit Windows 10 users. https://support.microsoft.com/en-us/...ent-in-windows If you don't allocate a pagefile, there can be problems even if you have gobs of physical system RAM. If you end up not using any disk space for a pagefile under your typical loads on your computer then you've lost nothing by allocating a pagefile, have you? You allocated /reserve/ space on the disk for a pagefile but don't use any actual disk space if your gobs of system RAM are always sufficient. You lose nothing by not using a pagefile but you gain safety by allocating the reserve for one. Side note: Burroughs acquired Sperry back in 1986. I wish Sperry had refused the buyout: Sperry was in the black and Burroughs severely in the red, so Sperry got dumped with a huge debt load. The company name changed to Unisys: a stupid name that might've looked good on paper but we then became Uni-sissies. The Burroughs OS would hang when it ran out of physical memory. Testing was a lot more thorough at Sperry than at Burroughs. When you wanted to most heavily use it, bang, it died. Don't ask for the details because I was lucky enough not to be one of the poor Unisissies that had to work on any of the Burroughs boxes, so I don't know what was the fix back then. |
#26
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows(Dell Precision T7400, upgraded from Win 7 Home)
VanguardLH wrote:
However, the OP got all of his system RAM available by changing a BIOS setting: enabling the VT-x virtualization option. But virtualization itself doesn't do that. At least one chipset in that family, supports memory mirroring on two branches of four channels of FBDIMM memory. That's like RAID 1, only for memory. P X Q X | | | | X X X X | | | | Quad channel Northbridge In the diagram, if an uncorrectable ECC error was detected on "P", then the chipset can use the value seen on "Q" as a replacement. This configuration also cuts memory bandwidth in half (as seen at the processor itself) When mirroring is disabled, it's just a regular quad channel chipset again. Since it's an ECC chipset, it can still correct errors on the DIMMs (at least until too many errors are present, and the location is "uncorrectable"). X X X X | | | | X X X X | | | | Quad channel Northbridge Mirroring happens to cut RAM in half. Memory mirroring, as a feature, should have its own line in the BIOS. It should not be toggled on and off via a virtualization setting. I don't want to leave people with the impression that a virtualization setting has "consequences". Normally, if you aren't aware of what virtualization is for, the setting can be on or off, and you would not care or even notice. These features are normally innocuous (until you need them). Then some software complains you don't have it or it isn't turned on. Paul |
#27
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
On Tue, 13 Nov 2018 14:21:08 -0600, VanguardLH wrote:
If you don't allocate a pagefile, there can be problems even if you have gobs of physical system RAM. If you end up not using any disk space for a pagefile under your typical loads on your computer then you've lost nothing by allocating a pagefile, have you? You allocated /reserve/ space on the disk for a pagefile but don't use any actual disk space if your gobs of system RAM are always sufficient. You lose nothing by not using a pagefile but you gain safety by allocating the reserve for one. Moreover, if you don't have a page file, you can't use all the RAM you have. That's because Windows preallocates virtual memory in anticipation of a possible need for it, even though that allocated virtual memory may never be used. Without a page file, that allocation has to be made in real memory, thus tying up that memory and preventing it from being used for any purpose. |
#28
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
Paul wrote:
VanguardLH wrote: However, the OP got all of his system RAM available by changing a BIOS setting: enabling the VT-x virtualization option. But virtualization itself doesn't do that. Yet the OP reported that the "hardware reserved" memory went away, so he could use it all. I don't know what BIOS the OP has or it there is a dependency in that BIOS. I didn't think virtualization would be the cause, so I never mentioned it but did say that it was likely something in BIOS that was preventing the OS from accessing all the system RAM. |
#29
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows(Dell Precision T7400, upgraded from Win 7 Home)
Ken Blake wrote:
if you don't have a page file, you can't use all the RAM you have. That's because Windows preallocates virtual memory in anticipation of a possible need for it, even though that allocated virtual memory may never be used. Without a page file, that allocation has to be made in real memory, thus tying up that memory and preventing it from being used for any purpose. Yes, once my PCs got to the point of having "big" memory (i.e. 8, 16 or 32GB) I got into the habit of thinking a page file was no longer necessary other than for crash dumps, but now I do prefer to have a small (e.g. fixed 2GB) page file, which means that the "junk startup services" get to sit idle consuming page file, rather than sit idle consuming physical memory, |
#30
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Windows 10 Home PC 32 GB RAM but only 16 GB available to Windows (Dell Precision T7400, upgraded from Win 7 Home)
"VanguardLH" wrote in message
... Paul wrote: VanguardLH wrote: However, the OP got all of his system RAM available by changing a BIOS setting: enabling the VT-x virtualization option. But virtualization itself doesn't do that. Yet the OP reported that the "hardware reserved" memory went away, so he could use it all. I don't know what BIOS the OP has or if there is a dependency in that BIOS. I didn't think virtualization would be the cause, so I never mentioned it but did say that it was likely something in BIOS that was preventing the OS from accessing all the system RAM. I'll boot the PC into its BIOS tomorrow and make a note of any version number. I'm almost certain that it is branded "Dell". The User's Guide says (page 79): "Virtualization (Off default) Specifies whether a virtual machine monitor (VMM) can utilize the additional hardware capabilities provided by Intel Virtualization technology." The manual is dated August 2007. |
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