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Windows Swap (Page File): Enable or Disable?
I have read in some newsgroup entries that it is meaningful to disable the page file if a pc has a lot of memory (8-16GB). Is this correct?
I ask because if this is possible for a pc with only an ssd, this would save a good block of space on the ssd.
It is possible, but it typically winds up wasting a small amount of physical memory.
When your system starts up, a lot of processes run that handle things like system services. Many of these processes dirty pages of memory that they will never access again for the entire life of the system. With no page file, these pages remain in physical memory for the entire time the system is running. With a page file, these pages will be copied to the page file as soon as the system hits any memory pressure, and the physical memory will be made free again. (The system can't just discard the pages because it can't prove they will never be accessed.)
You can measure how much memory this is by running the system with a page file, using it normally for an hour or so, and seeing how much page file space is used.
If you have significantly more physical memory that the system's working set is ever likely to be, this is insignificant and you can run with no page file.
On UNIX machines, there are other issues with fork and overcommitting physical memory, but they don't apply on Windows.
We have all seen the MS recommendation of 1:1 and 1:1.5 and all that info is rather old when ram sticks now cost $30 each. so it is important to see this MS referance also
2160852 MS themselves refers us to here where explained in human terms is this tidbit.
A common recommendation is to make the page file 1.5 times the size of the installed RAM. This recommendation makes sense only for computers with small amounts of RAM (256 MB or less). For example, there is usually not much point in allocating a page file that is 96 GB if the computer has 64 GB of RAM. The objective in such RAM rich systems is to avoid using the pagefile at all by providing sufficient RAM that all virtual memory can be in RAM all the time. If the virtual memory in use exceeds the amount of installed RAM, performance will suffer and having a larger pagefile will not help this situation.
There exists programs that will fail with the most stupid text displayed in thier errors, when a paging file is shut off via the operating system. There is also at least one Game that will fail when there is no paging. so I have always:
A) had enough memory for the tasks I was doing, or closed a few things down
B) avoided programs that are sooo poorly written that they do not follow the MS recommendations of proper dynamic allocations and just try to pig out on the whole wad :-)
The bare minimum: Keeping a 512M paging file around isnt going to kill anybody, it is much better than turning it off and not knowing why some program failed.
If you need a full memory dump, then you still need the full paging size, whomever can get through a 16gig memory dump is some sort of Genious, so I will leave that to them to decide.
