still about shared video memory: need to disable it !!!

Hi to everybody,
I know this topic has been discussed many times, but I am still confused about if there is a definitive answer or not.
Some premises:
- my motherboard does NOT have onboard graphics
- my graphic card is a nVidia Quadro FX 1700 with its own 512 MB DDR3 memory
- Vista reports that the device is working properly
- nVidia driver is 186.something (also downloaded latest 190.something, not beta, but I'm a bit reticent in upgrading something that currently works...)
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Problem:
I'm making tests with a computationally-intensive and RAM-eating application: ANSYS v.12 64 bits.
Well, there is some settings in Ansys with which I can force it to use any RAM available. But doing so causes a general Vista hangup anytime Ansys tryes to allocate also the RAM which is used for the Shared Video Memory.
I KNOW that "shared" shouldn't mean "stolen" nor "blocked", but the FACT IS that Vista doesn't seem to be sufficiently fast to de-allocate it in favour of Ansys, OR some allocation conflict arise.
Shared Video Memory, in my case, is as big as 2 GB or so, which is perfectly wasteful because there is NOTHING which needs 2.5 GB buffer for video.
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So, I absolutely need to force Vista NOT to use so large a Shared Video Memory, or best of all I'd need to disable it...
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Thanks in advance

cloche said:

Problem:
I'm making tests with a computationally-intensive and RAM-eating application: ANSYS v.12 64 bits.
Well, there is some settings in Ansys with which I can force it to use any RAM available.

Click to expand...

When you force a program to use all available RAM, you will freeze your computer. Have you ever used the 'Intel Burn-test'? It destroys your RAM and CPU, completely freezing Windows.

I KNOW that "shared" shouldn't mean "stolen" nor "blocked", but the FACT IS that Vista doesn't seem to be sufficiently fast to de-allocate it in favour of Ansys, OR some allocation conflict arise.

Click to expand...

Unless the graphics card is using it, Vista does not allocate any RAM. The reason it is called 'shared memory' is that it is available to either, when they need it.

Shared Video Memory, in my case, is as big as 2 GB or so, which is perfectly wasteful because there is NOTHING which needs 2.5 GB buffer for video.

Click to expand...

The more RAM your have, the more Vista will share.

So, I absolutely need to force Vista NOT to use so large a Shared Video Memory, or best of all I'd need to disable it...

Click to expand...

Bad idea. I don't even know if it is possible but you will not solve your problem by stopping Windows from sharing the RAM.



Off-Topic - When 12GB became possible for the average user, with the advent of DDR3 and tri-channel memory, people thought "I have 12GB of RAM, I can disable my paging file. YAY, I can reclaim that XGB of HDD space." Long story short, Windows and other programs will act strangely when you disable something that is meant to be running.

This post describes the effect better, they may be talking about the page file but it applies to shared memory as well, IIRC.

Hi Mattinahat,
thank you for your reply. I understand from it that I'll have to be very patient with Vista and definitively understand that, despite ANSYS being certified for it, I've done the very worst possible choice. Better had gone to some certified distribution of Linux (there are plenty supported by Ansys)... That's a thing I'll certainly tell my IT guys at work when it will come to upgrade workstations. Vista proves to be unuseful to anybody who wants to profitably WORK with it.
Let me explain why:
- if I, the user, decide that there is NO REASON why video memory should expand beyond what is installed on the board I'VE CHOSEN, I definitively want the OS respect that decision. Linux does. SCO Unix does. Mac "Tiger" does. Vista doesn't. It's the only one, so let me draw my own conclusions on it...
- Ansys v.12 is CERTIFIED for Vista. This SHOULD mean that Microsoft has given to Ansys inc. the specifications of its OS. When, with the appropriate set of commands, I ask Ansys to allocate all RAM available, I simply ask it to allocate any FREE RAM. Why the hell would this freeze the OS instantaneously, if nothing else is running except the Solver thread and the OS itself?!?? If an OS is not able to trap memory requests' criticities, let me once again draw the appropriate conclusions...
- I've got 8GB RAM. Vista uses 1.2 to 1.5 GB, according to its Task Manager&Co. So the free RAM should be at least 6.5 GB, if not 6.8 GB. Why the hell should the OS freeze any time I request Ansys to reserve a free block of at least 6 GB RAM ??? Curious: it works with 5.5 GB... But where would the remaining RAM "disappear" ??? And why would I bother with these absurd tunings? If I understand correctly the definition of Vista, this should be an "OPERATING System", shouldn't it?
OK, thanks again, I'll have a look to the other link you post. This seems to be interesting. The more I learn about the deficiencies of Vista, the better it is, at home and at work!!!
Regards

ok ive had a poke around the interweb as i was interested in this too , theres plenty of others wanting to do the same thing but as of yet no one has come up with any answers only suggestions which dont work , even microsofts own tech forums have said "its a hardware issue contact your hardware vendor"!!??

Ive poked about in my bios as i thought the answer would be there but it seems not

anyway this is a longshot but maybe worth a shot

start/run/msconfig

boot tab/advanced boot options put a check in "maximum memory" and allocate you total ammount of physical ram im MB...........i dont know if itll work but its the only thing as far as i can tell hasnt been tried by anyone yet

Archie

On my side of the pond (win 7) checking Max memory has caused many many problems rangin from failure to boot, to random BSODS, etc. Im not sure that vista does the same but thought you should know.

in win 7 we leave max memory unchecked, max cpu unchecked, legacy floppy support disabled.

BTW, OT I enjoy reading your posts good info and well written

Ken

zigzag3143 said:

Archie

On my side of the pond (win 7) checking Max memory has caused many many problems rangin from failure to boot, to random BSODS, etc. Im not sure that vista does the same but thought you should know.

in win 7 we leave max memory unchecked, max cpu unchecked, legacy floppy support disabled.

BTW, OT I enjoy reading your posts good info and well written

Ken

Click to expand...

well it was originaly suggested as a fix for the 3.5gig ram limit in 32 bit operating systems and as a fix for 64 bit systems not seeing all the physical ram , it didnt work of course but i heard no reports of any major hassles with Vista although ive not tried it myself.

Ive not been around my own PC for that last couple of days ill give it a go tonight and see what happens