Page File - Why set one for each drive?

I have Windows Vista Business Edition running on my laptop (brand is HCL). I have 4 HDD which are as follows -

C - 29.2 GB (of which only 3.68 GB is free) D - 39 GB (of which 37.8 GB is free) E - 39 GB (of which 37.3 GB is free) F - 41.6 (of which 41.4 GB is free)

However, my page file settings are as below.

Automatically manage paging file for all drives.

Question -

Why should I set one for each drive? Should I set my page file on the OS Root Drive. I happen to talk to a System Administrator in an IT company and he advised that we should never set the page file on the OS drive but on an alternate drive wherever possible.

It would be really helpful, if you can guide me here or at least point me to the right resources so that I can read about paging and best practices of paging.

Cheers,

Solution 1:

Multiple page files are processed paralelly to split IO operations, which noticeably increases the performance.

In our disk queue and total time tests we have recorded up to 3 times better performance using 4 pagefiles on 4 sata HDDs on heavy usage on Windows 7 with 2Gb RAM.

Here is a simple article on the subject:
Learn Best Practices for Optimizing the Virtual Memory Configuration

Solution 2:

From Mark's post on Pushing the Limits of Windows: Virtual Memory

You’ll notice that the default configuration is for Windows to automatically manage the page file size.

When that option is set on Windows XP and Server 2003, Windows creates a single paging file that’s minimum size is 1.5 times RAM if RAM is less than 1GB, and RAM if it's greater than 1GB, and that has a maximum size that's three times RAM.

On Windows Vista and Server 2008, the minimum is intended to be large enough to hold a kernel-memory crash dump and is RAM plus 300MB or 1GB, whichever is larger. The maximum is either three times the size of RAM or 4GB, whichever is larger. That explains why the peak commit on my 8GB 64-bit system that’s visible in one of the screenshots is 32GB.

From what I remember,

• the defaults place a single Page file in the boot partition.
• And, it is counterproductive to have multiple page files.
• But, it is useful to have the Page file in a different drive
  (not just different partition) from the boot drive.

Solution 3:

No matter what the initial reason for implementing the pagefile system was, pagefiles are still used, even heavily used by Windows today as nowadays available software has developed as well, not only available RAM, and are much more demanding today than they were back in the days when there's much less RAM available.

Especially on gaming PCs there are programs running which need a lots of your installed RAM to perform properly, but also video post processings, packing/unpacking, streaming and such processes ... at worst all at once, require a place for Windows to swap data which are not urgently needed at the moment but will be needed later again. And that's what the pagefile is for.

Always let Windows manage this file/those files, unless you're absolutely sure what you're doing and know how large it should be (btw, Windows already recommends how large it should be). To prevent unnecessary fragmentation and HDD activity you can set a fixed size by setting the same value for min and max size. This way it won't be shrinked and then increased again depending on the workload. But to set the correct sizes you have to have a proper understanding of what Windows is doing with it and when.

The old 1.5 times your RAM rule still seems to hold true, as this is always Windows' own recommended pagefile size. So, for a 16 GB RAM machine it would be something about 24 GB pagefile size (recommended).

I don't know if it is useful or maybe even bad to have several pagefiles, I for one have a fixed size of 2 GB min/max on my boot drive (HDD) for partition C and a managed one on an SSD. But I was searching for pros and/or cons to have more than one pagefile or not, as I tend to delete the 2 GB on my boot partition. Alas, haven't found any valuable arguments yet, but I assume, just for the crash dump files and stuff, it's useful to allocate some GB for Windows' where the pagefile resides normally by default. Hence I leave it like that. But for the other SSDs where my games are installed I do not have any pagefile. Wouldn't even know which size they should have to make a difference, whereas I also don't want Windows to occupy another up to 24 GB on each SSD (or at least 16+ GB as it uses now for the managed pagefile).