I've been having problems on Windows 10: periodically I get a "low memory" warning. A lot of the Super User questions on this topic talk about driver memory leaks, but as I'll explain below mine doesn't fit the criteria found with those. What normally happens for me is my page file gets to about 70-80 GB in size as my "System and Compressed" memory grows. Eventually I start getting low memory warnings until I reboot, and then I'm good again for 5-8 days.
There are a lot of people who complain about System & Compressed memory growing to the point where it causes problems, but unfortunately the common cause (driver memory leak) in those doesn't appear to be immediately the problem for me.
Firstly, Windows 10 high memory usage (unknown reason) covers a common problem. However, note that a key indicator in that scenario is a high "Non-Paged" memory usage. In my scenario, non-paged memory is not being used that much; I have 16 GB of memory, and I can have 8-9 GB of "System and Compressed Memory" and less than 1 GB of non-paged memory.
The question I linked to suggested utilizing the PoolMon tool. I have done that. The high Nonp processes I've observed have been those with the tag "Thre" and "Py28" and from what I can tell these are not drivers (most Q&A on high system memory usage in Windows 10 will point you to a driver leak).
Another symptom of my issue is that the longer the system is left on, the larger the pagefile gets. For example, before the last reboot the pagefile got to be about 60 GB in size. Also note that I see on my Task Manager screen "Committed" values regularly in the "12.3/50-60 GB range." I have no idea if that is normal or not. But it would at least seem "weird" to me for my page file to get so large.
Edit: Let me make clear what I'm asking here. I am asking, "How can I tell what application is using so much of my system's memory when it appears that System & compressed memory is obscuring the root memory hog from me." Note that again, I have a pagefile that gets up to 80 GB or so in size and NO single application has high memory usage, only the "System and compressed memory" system process. Under older versions of Windows I knew how to tell what applications were using so much memory, but NONE show abnormal memory use now. I don't know if this is because System and compressed memory is "being helpful" and helping manage the memory so the system can run for much longer without running out of it, or what, but I know that I'm running out of memory on my system and no application EVER shows abnormal memory usage in task manager. I'm asking how to find out what is causing this. The closest I've found to an answer for this suggests using PoolMon and looking for an offending driver using large amounts of non-paged memory, but unlike people who have had driver memory leaks, my non-paged memory usage is never very high at all, and no drivers are listed as high memory users when I ran PoolMon.