Dual video card questions.

[GermanyChris]

Ok so I upgraded the new MP to 10.7.5 and installed a GT 430 I had laying around to go with the 4870 thats in it 4870 in slot 1 GT 430 in slot 2 both set as 8x. Main monitor in the 4870 secondary in the 430.

I fire up cinebench to see how that effected the 4870. Cinebench doesn't even offer to test the 4870 and only bring up the 430. I run the test expecting the the low score that the 430 has always given me and it beats the 4870. It shouldn't be doing that at all..

Whats up?

 

[GermanyChris]

Since I'm getting extra performance out or the 430. Would I gain extra performance if I went with 2 2GB 550Ti

 

[scottrichardson]

Is your desire to run 1 display from each card?

From what I recall, spanning across two GPU's isn't as efficient as running both displays off the one card.

The system has to pass the video data from one frame buffer to the other when you do things like move a window from the left display to the right display. You will notice there is a drop in framerate/responsiveness when you do this if you are running one display per card.

I purchased a 4870 and a GT120 with my 2009 Mac Pro, thinking I would run 1 display on each card. Until I tested it and realised it was MUCH faster running both displays on the 4870. My GT120 just sits there doing nothing now!

Scott