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tl;dr 22GB RAM, SSD, pagefile, yes/no? Reduce mapped files reserved memory yes/no? how?

I am running Windows 7 on my work desktop. It has 22GB of physical RAM. I am running it with an SSD. The regular HDD in this computer is rarely used. I have disabled the swapfile, because sometimes rogue programs would go up and make it run up to crazy sizes, like 60GB filing up the whole SSD. I can't xif that program. Although, I could renable the swapfile and set a max size of something sane. I'm calling it swapfile here, but windows calls this pagefile, and swapfile is something else.

Here's the problem. When the commit charge gets up near 22GB, Windows doesn't like it. I get low memory warnings, program crashes, screens going black while the graphics driver or something crashes, etc. The computer wants 4GB of standby memory for "Mapped Files". This effectively wastes 4GB of physical memory when their is no swapfile.

So my choices are :

1) Let there be a 4GB swapfile on the SSD to raise my commit charge, so I can use all the physical memory. But a swapfile on the SSD will degrade the SSD faster and slow down performance anytime Windows decides to put something important in the swapfile.

2) Put the swapfile on the HDD, to protect the SSD, but this causes much worse performance problems. If anything decides to actually use that swapfile, the whole system slows down like crazy.

3) Leave things alone, and let the 4GB or so go wasted, and put up with the low memory warnings and problems. Or to prevent that, use even less physical RAM for programs.

Solution 2 is obviously unacceptable. So the question is, which is the lesser of two evils, 1 or 3?

Or is there a solution 4, something like not let Windows reserve so much for mapped files. If it's possible to not let Windows use more than 2 or 3GB for mapped files, that'd be the ideal solution. Then I'd only get the low memory problems when I am actually using more of the physical RAM. I wouldn't need quite that much so often.

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  • How come 22GB RAM? 8+8+4+2?? if you're really using these amount of RAM please consider adding/upgrading another 8GB stick at least.
    – lex
    Jul 23, 2015 at 18:08
  • You do know you can set a physical limit the file will grow to right? You can write GBs worth a data every day and the device will last years in most casts.
    – Ramhound
    Jul 23, 2015 at 18:19
  • You belief that reducing the RAM used by mapped files would help is wrong. The commit charge relates to the total amount of virtual memory processes have requested whether they have used it or not. Windows guarantees this will be available so it has to be less than RAM + pagefile. If the processes actually started using the memory the mapped files would start to be removed from standby memory. Jul 23, 2015 at 18:24
  • The computer was built with 4 + 4 + 4, and then I added a 4 + 4 + 2 that was laying around unused. Of course it would be better to replace that 2 and some 4's with 8's, but that would cost money, and there isn't room in the budget right now. Jul 23, 2015 at 20:11
  • David, you would think what you said is true. However, if that's really true, then the computer shouldn't start freaking out when at 17.8/22 used, and 21.8/22 commit used. Ideally, the computer shouldn't have any memory complaints until 21/22 physical used, right? Something weird is going on. Do you have another hypothesis to explain why I get low memory symptoms based on the commit charge, not on the physical? Jul 23, 2015 at 20:15

1 Answer 1

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1) Let there be a 4GB swapfile on the SSD to raise my commit charge, so I can use all the physical memory. But a swapfile on the SSD will degrade the SSD faster and slow down performance anytime Windows decides to put something important in the swapfile.

(my boldface)

The above is a myth. In a reasonable workload and with a properly spec'd SSD flash endurance isn't what will kill your drive within any reasonable amount of time. The exception to this is pretty much if the drive is faulty to begin with, which is what warranty is supposed to cover.

Swap space has significant uses even when there is plenty of RAM available.

Just put some swap on the SSD. A few gigabytes is likely plenty, but this depends on your typical and peak (memory-wise) workloads. If your system has plenty of RAM compared to its normal workload, it's likely that the swap won't see much use, but the swap space will be there if the memory manager decides that using swap is a better tradeoff than evicting cache from RAM. If your system is routinely memory starved, then you definitely want swap for now; add some more RAM later on and keep the swap space around for exceptional loads.

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