Dual Graphics Cards?

[rpacker]

I would like to know if it will improve Resolume performance if you are using dual graphics cards, one for the application and one for the projection output. I have heard that you shouldn't have both the application output and the video output share the same graphics card. Is this true? Also, if you use two graphics cards on one computer, does this diminish the processing of each. Each graphics card takes up two slots on a Mac.

Thanx.

[ridiculoid]

I asked a similar question here once, the answer was that Avenue does all processing on the main card. If there is a second card, any output is a duplicate of information from the first card. So, that would suggest that a second card won't improve performance through sharing the load, it just gives you more outputs to play with.

[Basic]

What FPS are you getting and what is the res of the clips your playing?

[rpacker]

I am using two instances of a single 720p clip in DXV format. Depending on which graphics card I am using for the projection output, I either get 20fps or around 50fps. The faster card is delivering the slower rate for some odd reason, so I am wondering if using two graphics cards causes problems, and if I should just use one.

[Joris]

I have heard that you shouldn't have both the application output and the video output share the same graphics card. Is this true?

In short, no, it is not true. There is no problem with using a single output for both the app and the video out, it is actually the suggested and preferred way. Adding more GPUs to the mix will not increase performance.

In fact, we even recommend using Matrox Triple or DualHeads when you want to have multiple outputs. When you absolutely, positively need to use multiple GPU, try to at least get the same model and make.

I hope that clears things up a bit.

Joris

[rpacker]

Thanks so much for the clarification. There seems to be little or no published information about the use of graphics cards for multimedia performance and projection. I think someone needs to write a book!

[jbarro]

Hello. I just bought my second ATI HD 5770 for my Mac Pro. I thought that it was better than use a Matrox Triple Head.
May I combine two ATI HD 5770 card with maybe one or two matrox triple head to reach the maximum Arena composition resolution 8.192x8.192? is that crazy?

[GeeEs]

Good luck with that resolution... I don't think any PC can deliver such amount of pixels rendered in realtime these days , not even with a SSD.. But i hope i'm wrong

As stated above, Dual graphics cards won't help you performancewise, while Avenue/Arena uses one GPU.

Personally i think you only benefit from SLI/Crossfire if the fastest high-end card on the market these days is NOT fast enough for your software/game/program. That said, you need also software that fully support SLI/Crossfire, and -as said- unfortunately Avenue is not that kind of software.
In some cases though, it can be nice to use SLI/Crossfire when the price for 2 older/slower models is lower than the price for 1 brand new fast GPU...

Why do you think dual GPU is better then Matrox?? I'm using a Matrox Triplehead for 1 year now with dual and triplehead setups... no sweat! Works great! Every time again.

[jbarro]

ummm, I bought my second Ati HD BEFORE know that Resolume only uses one GPU. I guessed Matrox is better for notebook config, after all, the Mac pro allows you to install two Ati, so I prefered to use internal cards than external like matrox triple head. maybe I was wrong...
anyway, I hope is possible to use just ONE Ati conected to TWO matrox triple head, one to each mini display port, that means 6.144 x 4.608 output in 6 different 1024x 768 I guess.... if not, I'm going to come back to Dataton Watchout! and I don't want to!

[GeeEs]

In this thread some users are testing codec performance results, also with some extended setups. It seems that 2 matrox dualheads on one card worked well on Avenue 3 on 4000 px (but is still a bit jerky on 8000 px horizontal resolution in Avenue/Arena 4 beta....)

http://www.resolume.com/forum/viewtopic ... rox#p33042