#Page Faults — Micron
19 messages in this thread
I'm having page faults on two Micron P120's when rendering very large images…
There seems to be enough space for the machines to swap into, one is configured
with HIMEM/EMM386 and the other with QEMM, both are setup with Vibrant's
generic VGA, both are running Microsoft's network drivers, and both have
standard CFIG386 setups…
What can cause a "page fault" crash?
Has anyone else experienced problems with new Micron P120s?
Thanks,
Donald Newlands
Why are you using QEMM? I have a Micron and I never use QEMM when running 3DS –
I would not be surprised if QEMM (esp. if you have Stealth mode turned on) was
the cause of your page faults.
Page faults are software problems caused by software not hardware unless you
are starting to have Memory chips go bad. There should be a diagnostic dump
which you can read and see where the page fault occurred.
Judy
>> Why are you using QEMM? I have a Micron and I never use QEMM…
Judy,
Myself and most of the people I know in this business use QEMM for memory
management (and I've used it from day one on my Micron!). It would not be
the _type_ of memory manager you are using that would give you a page fault
error!
>> Page faults are software problems caused by software not hardware…
WHAT? The most obvious problem would be that a memory address is being
stepped on. …a memory address is used by a piece of _hardware_ and it's
memory address is not being excluded (X=A000-CFFF) from whichever memory
manager you are using (whether it be EMS386 or QEMM or ??). That being
said, the software is trying to occupy a memory address that hardware is
already using.
Please be careful in your answers to these types of problems.
Personally, I would reccomend a clean system boot as a starting point for
diagnosing.
Ralph
Ralph –
Guess what – it is firmware not hardware that uses memory. And I can assure you
that QEMM in STEALTH mode (as does 386 MAX, Cloaking devices etc.) causes a
host of problems with various applications.
QEMM being the most popular OEM memory manager tends to be a leading source of
problems. But if you really know your operating system you can get just as much
free conventional RAM with EMM386 as you can with QEMM. I would never recommend
the use of QEMM unless someone is hopelessly lost where DOS memory
configuration is concerned. It is a convenient crutch – but a dangerous one!
Judy
>> Guess what – it is firmware not hardware that uses memory.
Which is the way a piece of hardware communicates with the system, right?
And it's the memory segment that it uses that can get stepped on if it's not
excluded from your memory manager.
Listen Judy, I don't wish to debate with you the virtues of QEMM over
EMS386. Either one can do the job.
Surfice it to say that if I had 2 machines using 3DS, getting the same
problem page fault …one with EMS386 and one with QEMM… I would not
suggest dumping QEMM. It's just not the next logical step.
Ralph
Judy:
>> if you really know your operating system you can get just as
>> much free conventional RAM with EMM386 as you can with QEMM.
Agreed. But that's not the main reason we use it. We did a series of tests
here, and the rendering speed using QEMM was much better than EMM386, which is
why we standardized on it. I've heard that different machines have different
results, though, so I'd check both. Having more base memory doesn't help out
3D Studio much, I'd test for pure rendering speed, assuming that's what you do.
Greg Pyros
I don't use either QEMM and I use the NOEMS parameter if I use EMM386. I am not
the one having a problem.
Judy
Judy:
>> I don't use either QEMM and I use the NOEMS parameter if I use EMM386.
>> I am not the one having a problem.
I didn't say that you were! :^) I just commented that on most machines, but
not all, QEMM gives faster render times than EMM386.
Greg Pyros
>>>But if you really know your operating system you can get just as much free
conventional RAM with EMM386 as you can with QEMM.<<<
Judith, I have 128 meg RAM. How can I get EMM386 to recognize it please?
Thanks,
Will
Judy:
Perhaps you know a method to see RAM above 64 megs without using QEMM or other
memory manager. If it can be done with EMM386 then please post it here as
this question comes up all the time. There are a lot of animators out there
relying on QEMM to see all of their RAM, you could save them all a bit of
money. Thanks for your assistance.
– Bob Ritger
Judy,
Actually, the faults have been happening under HIMEM/EMM386 on one machine and
under QEMM on another… The machines are otherwise identical.
We haven't used Qemm since we got rid of our Targa+… At the time, I found
Qemm was slightly faster than Himem on some machines, and also had a zillion
switches which helped us get some pretty wierd combinations of hardware and
software to work.
<<QEMM in STEALTH mode (as does 386 MAX, Cloaking devices etc.) causes a host
of problems with various applications.>>
I read the same —
Thanks,
Donald
Ralph,
<<The most obvious problem would be that a memory address is being
stepped on. >>
Thanks! — I haven't seen a page fault in a long a few years, but the last
time it happened, that was exactly it.
–Donald
Judy:
A "page fault" is NOT a "problem", software or hardware. A page fault is when
the virtual memory manager (in this case, Phar Lap's) tries to access a virtual
memory page that is not currently in memory (ie, it has been paged to disk).
When the page fault exception occurs, the VMM brings the page into memory and
restarts the instruction that caused the page fault — thus the application
software never knows the data wasn't there all along.
Now, of course, there can be an error that occurs DURING a page fault, and I
would agree that running 32-bit DOS extender software such as PharLap with QEMM
stealth-mode enabled is kind of asking for trouble, but I have NEVER had a
problem with AutoCAD, AniPro or 3DS that was caused by QEMM. (FWIW, the "dump"
that QEMM often gives with an exception error is a "feature" of QEMM — it's
reporting a condition that DOS doesn't — so whereas DOS would've just locked
up or dumped you out of the program, QEMM gives you some help in trying to
discover the cause.)
Dave
Dave,
<<A "page fault" is NOT a "problem">>
Thanks for the clarification!
Donald
Actually you can get a DOS dump if you use the "err>err.out" parameter when
running. Standard parameter when you beta test games.
Judy
>> I'm having page faults on two Micron P120's when rendering very large
>> images…
>> What can cause a "page fault" crash?
Donald,
Have you tried booting with a clean system (bare config.sys and
autoexec.bat files)?
Have you excluded hardware memory addresses from QEMM and/or EMS386 that
are being used by your network adapter and VGA card?
Are you sure you are not running out of swap disk space?
Let us know how it goes.
Ralph
Ralph,
<<Have you excluded hardware memory addresses from QEMM and/or EMS386 that are
being used by your network adapter and VGA card?>>
Thanks — I'm pretty sure that must be what's happening…
I haven't tried them "clean" yet — they're other people's workstations that
I'm pulling in as slaves.
I'll let you know what works!
Donald
Donald,
If these are rendering slaves, I would recommend starting with a clean
slate. Make a "generic" config and autoexec, then let memmaker do it's stuff,
agressively scanning memory. Let it create exclusions, blah blah blah. Go to a
basic bios setup, and then turn off all your shadowing. Then render a frame,
see what happens. Then I would recomend turning everything slowly back on in
this order:
1. Bios Settings
2. Shadow Settings
3. Driver loadings
4. QEMM use
Also, defrag your drives.
Good Luck!
Chris
Chris,
Thanks for the clear step-by-step info!
Donald