[snippage]
I have two SATA SSD's in my Win10 desktop PC, 250 & 500 GB. I did not
expect
Win10 to allow it but I tried and it worked. I created a pagefile.sys
on
each drive. It noticeably speeded up Win10. Then I booted WinXP in
VirtualBox, on that PC, it was even faster than native WinXP installed
on my
netbook PC. I reason that the moving data on one drive only involves
directory changes, while moving such data between two drives, actually
involves slow data transmission. Twice the bandwidth to pagefiles in
unbeatable.
Are you certain that Windows can use multiple pagefiles simultaneously?
I'm only asking because I don't know, I did find this, not sure if it's
correct:
"Windows can use multiple page files just fine. Best practice is to
have one page file on each physical drive, assuming they're not
RAID'ed. A single drive would only have one page file, not one per
partition (for performance reasons). When a paging operation is needed,
Windows will choose the page file on the least busy drive at that
moment."

http://www.tomshardware.com/forum/25...le-size-drives

Thanks Mike,

I just checked my Win10 Resource Monitor. Yes, the pagefiles on C: and
D: are both used, but it depends on what is going on. When I open D:\,
D:\ pagefile.sys is active. But C:\ pagefile.sys is always more active
than D:\ pagefile.sys . Seems to confirm my hypothesis.

Using two pagefiles on each SSD saves me 1.2GB in RAM memory. That's a
god send and facilitates use of virtual OS(s).

I tested this under Windows 10, and it froze the machine twice.

I didn't use your exact test setup. I could have, but all
I wanted to prove by running a test, is that there is potential
danger. It looks to me, that if there is malloc going on when
the paging is heavy (but can't keep up), the system just freezes,
instead of slowing down to the (rate limited) paging activity.
It doesn't even seem to work as well as WinXP.

Because it has that sensitivity, I can't recommend this to
potential users, since it relies on the speed of the storage
being maintained once the system is driven into swap country.

I had a similar problem with Imagemagick, and its usage of
OpenMP library as part of image processing. Once a bunch of
processes started drawing down on memory at the same time,
the system would freeze there, too. Microsoft fixed that,
as on the next OS release, it would no longer freeze. But the
test I've just done suggests the other fix was just
a bandaid to solve that particular case, rather than an
actual "good fix".

If there is no virtual memory left, a program should
just die, rather than freezing the computer like that.
Freezing the computer isn't user friendly.

There's not much point of having a page file, if the
system won't use it. And just augers into the ground
when free RAM on the system drops below 400MB or so.
The cool part is, the IDE LED stays lit. As if some
I/O operation needed RAM, and there wasn't any to be had.

On VirtualBox, you can highlight eight VMs and click
the "Start" at the same time, if you need an
aggressive test case. My suspicion is, if you started
enough VMs simultaneously on your two SSD setup, your
system might freeze as well.

Paul

Maybe I should explain how I did this. Go to System Properties. At the top
of the virtual memory page is a button, "Automatically manage paging file
size for all drives". Uncheck this button. C: drive page file is still
"System managed". You should then be able to make D: "System managed". I
think that manually setting the pagefile upper and lower size limits might
be an error that causes your problems This worked well for my Win10 PC. When
I see that I have gained 1.2GB in free RAM, I ask from where. Answer, The
second pagefile on D:\ allowed 1.2GB of memory contents to be paged out.

I have started two VirtualBox VMs, Puppy Linux (actually started yesterday)
and now WinXP. There is still ~100 MB free Win10 memory. WinXP Task manager
says only 1-3% CPU is used. I don't want my system to crash but it still has
enough resources to permit Waterloo Maple to run.