PhysX Memory Usage Tests

[Evildead666]

So I've been playing around finding a use for my venerable old 8800GTS-320, and have been having fun getting PhysX running on an ATi display card, using hacked drivers and the above 8800GTS.

I am weird as in I actually enjoy benchmarking, really enjoy it. (sad git I am).

So here's the latest batch :

Crazy Machines 2 demo, and Batman : Arkham Asylum.
How much memory does the extra video/PhysX card need ?

Now, I have a kvm switch so the 8800GTS has a video out, it just goes nowhere. No screen for it.
Its not a 'dedicated' PhysX card, but its not being used to render the final image either, so it could be using half of the shaders, or more. or less.

Memory usage was something I had been meaning to test, since the release of the 275+250 combo card for halloween, 384Mb of RAM had been deemed sufficient for the dedicated PhysX card.

Here are two screenshots, with the important (memory) part circled in green.
Both games were tested using 1680x1050 res.

Crazy Machines 2 PhysX Fluids Level, the 16th one of the 20 demo levels.


and Batman : Arkham Asylum, quick smack and run, got to see smoke, spark, and cut some ribbons


If anyone else could share some memory usage info at 1920x1080 or 1920x1200 I would be very interested to see if the PhysX card needs more memory at higher resolutions or not.

Probably, but scientific knowledge comes thru testing

[VJ]

I'm not sure it would... the originial PhysX card didn't have *that* much memory...

But euhm, what is preventing you from running the games in lower resolution? It should be possible to draw conclusions if there is a connection between resolution and memory usage.

[Evildead666]

Its possible to run in lower res.
I'll give it a go this weekend.

The original Ageia card is not really supported anymore.
It doesn't have enough memory to cope with the larger tasks, and the newer functions are written for cuda, and not direct Ageia stuff. afaik.

Crazy Machines is crazy addictive tho

[VJ]

I'd be interested to know... I currently have an XFX NVidia 9600GT with 512 MB as my main video card, but it was bought with possible future use as PhysX/Cuda card in mind.

Do you still need hacked drivers to combine with an ATI? I thought these things were settled (but maybe only in Windows 7...?)...

[Evildead666]

Yes, you still need the hacked Nvidia drivers.

9600GT has 96 shaders doesn't it ?

I'm using Win7 RC still, but I read it was possible in XP, though I haven't tried in XP.
All of my games are in Win7 64bit...

Will be doing some benching today

It got down lower than -8C here last night..shame I can't use that to cool the PC...

edit : just noticed a line in caps. corrected. Keyboard going to be punished.

[Evildead666]

Arkham Asylum at 1280x1024:


Cryostasis at 1920x1080 (my monitor actually displays it, just blurry)


Cryostasis at 1680x1050 :


Cryostasis at 1280x1024 :


Cryostasis at 1024x768 :


Crazy Machines at 1920x1080 :


Crazy Machines at 1280x1024 :


Crazy Machines at 1024x768 :


It seems the memory for PhysX does NOT vary with the resolution.
The variance here is pretty small within the same game.
Some Games use more than others though, and I have yet to find something using more than 275Mb of GPURAM for PhysX.

[Evildead666]

9600GT seems to have 64 shaders, 32 less than a 8800GTS 320Mb...but it does have faster clocks for core/shader, and can probably overclock to be on almost equal grounds...
Bench it, see what happens

It'll be better in 3DMark Vantage due to it helping the CPU score...

[VJ]

I honestly don't know much about the technicalities of the card. I just wanted a more or less current card that wasn't too expensive, cuda capable and occupied a single slot (for future options). While I found one, the one I have differs visually from the ones shown on the website: unlike on the imeges, the fan on mine is all the way near the front of the card (where the monitor connectors are), so while it theoretically occupies one slot, anything put in the slot next to it (even a low profile card) will block airlfow.

It is the only video card in the computer, and I don't have that computer with me know (still needs to be shipped over here).

Interesting to see that the memory use is quite constant... Perhaps it is not related to resolution, but to the number of objects and their complexity in the scene?

We actually reached -20°C here (Warsaw), with predictions of temperatures going as low as -23°C. The windchill factor makes it feel like -25°C and they predict it will even feel like -31°C...

[Evildead666]

Better get the thermal undies then

[Evildead666]

Since Nvidia released their dual GPU pick and mix card, with the 275 and 250 onboard, and stated that the maximum memory needed for the PhysX part would be 384Mb, i'm wondering how they got to that figure.

I never really got above 275Mb, but I only have 96 shaders.
What if the memory increases with shader count ?
another 25% on 275Mb would give about 366.6666Mb....Just shy of the 384Mb.

PhysX in its gaming version is probably limited to 128 shaders, just because there has to be a programming limit somewhere...

[VJ]

Perhaps they also never reached 384 MB, and just said: "Well, let's add 30% more, that ought to cover the near future..." (it wouldn't be the first such statement in computer history )

I have been looking at adding a second video card (as primary card), but the main requirement for me is noise: it should be silent when doing relatively easy tasks (up to and including playback of HD content). The one I have is fairly quiet as when not pushed too far (haven't tested HD playback yet), but I'm guessing the Asus Matrix series is then the line to look at?

Jörg

[Evildead666]

Quite nice coolers, just make sure the air is blown outside of the case rather than into it...
iirc the matrix coolers do both...

http://lokalhoszt.hu/pics/keptarto/Skizz_20081031_asus_matrix_radeon_hd_4850_02.jpg

http://www.pretaktovanie.sk/obr/dosky/Asus_P6T_Dlx_preview/Asus_Matrix_cards_cooling_1.jpg

http://www.asus.com/product.aspx?P_ID=JZZ6X5y8CW0AqFtv&templete=2

[Evildead666]

I'd wait until the new cards have come out on custom PCB's and custom cooling.
So far, they are nearly all standard cooling/cards...and Nv hasn't shown up to the party yet

[VJ]

Yes... the purhase isn't for immediately though (not really needed + can wait for DX11), but it is just odd that it is so hard to find reviews that not only care about speed, but also about noise. The 9600 I have is by XFX, and I was pleasantly surprised by its idle noise level. Downside to it is that it doesn't expell hot air from the case (occupying only a single slot).

I'm somehow guessing that nowadays, coolers tend to be more intelligent...

Jörg

[Evildead666]

Most of them are cheap and just pretty....sadly