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View Full Version : 3x NVidia Quadro NVS 450 => 12 screens



Nicolas Lelong
11-03-2010, 06:33 AM
I have a machine at hand, with a Core i7 CPU, and 3 NVidia Quadro NVS 450 cards, each connected to 4 1920x1080 LCD displays.

I need to run a simple but smooth 60Hz OpenGL animation on this system.

For now, I'm at loss, I tried :
- creating a single GL window for the whole 8K x 3K desktop ; just using glClear on this _very slow_
- creating a window per screen, each with its context, once again just using glClear is _slow_ (but better than above)

Does anyone have experience to share with this kind of setup ? Such as achieving 60Hz display of anything on the multiple displays ?

Cheers,

Nicolas.

Groovounet
11-03-2010, 07:35 AM
Hi,

The Quadro NVS 450 is a really slow chip... you can't expect great performance. When you say "slow", you do mean that do don't even have 60Hz with only a glClear?

Your framebuffer worth 100 MB... 6GB/s @ 60Hz (hopefully dispatch across all cards but I believe copied on all cards) for a maximum of 11GB/s... It might be tricky quite quickly.

12 screens... nice!

Nicolas Lelong
11-03-2010, 08:12 AM
The Quadro NVS 450 is a really slow chip... you can't expect great performance. When you say "slow", you do mean that do don't even have 60Hz with only a glClear?

Yep, I did not expect stellar performance, but even with only a glClear, it can't sustain 60Hz, or even 30Hz... I did not bother to measure the actual framerate as the refresh is really perceived as _slow_...

12 screens should be a nice playground, just have to figure out how to animate something on them... :P

david_f_knight
11-03-2010, 11:36 AM
Do you have multisampling framebuffers and multisampling enabled? For the best possible performance you should not use any multisampling.

Nicolas Lelong
11-03-2010, 02:45 PM
Do you have multisampling framebuffers and multisampling enabled? For the best possible performance you should not use any multisampling.

No, no multisampling, no depth buffer, no stencil buffer.

Tried to see if WGL_NV_gpu_affinity could help, but the boards does not support this extension.

Trying to setup a WinXP instead of Win7 to see if it helps.

Nicolas Lelong
11-04-2010, 03:03 AM
Trying to setup a WinXP instead of Win7 to see if it helps.

It helps ! On XP32, we're now able to run a simple GL window on all the 12 screens, running a smooth 60Hz white quad moving above a green background...

Now, I got to display more real things.