Benefits/drawbacks to dual/triple graphics card builds

[MrCarder]

I keep seeing some of the lower end GFX cards (that are in the buyer's guide) go on sale, but I rarely see the higher end one's drop in price.

What exactly does a dual card setup do? Does it just double my specs? Say I buy a GeForce card with 500 CUDA cores - does doubling them up give me the same performance as a card with 1000 CUDA's?

Also, are there any drawbacks to a dual card system?

 

[rwillett]

I have a dual 5770 setup in my Hackintosh.

The reason for this is that I have a genuine Apple 5770 and use Final Cut Pro X. The 5770 really works very well with FCP X. So that was the starting position. I looked around for a second card, partly as I thought it might help speed things up, but partly curiosity.

I got a cheap Asus 5770 and it works perfectly well.

The advantage of the dual cards are:

1) The older cards are dirt cheap.

2) They are quite low powered compared to new ones. However two of them consume more power.

3) You get multiple display outputs. My main 5770 drives a 24" display, the second 5770 drives 2 x 17" displays. I never got all three ports of the 5770 to work properly.

4) Some programs will take advantage of them.

The disadvantages:

1) They aren't as powerful as the newer cards, e.g. 2 x 5770 = 0.9 of a R280x.

2) Two 5770's consume more power than one R280x. You may need a bigger PSU.

3) You can't mix and match different CPU's

4) They take up more space in your case.

Rob

 

[MrCarder]

Thanks for sharing rwillett! I can see how having a second, completely separate card could come in handy. Maybe I could actually watch something while rendering video on another.

I was a big time Final Cut fanboy, but I switched to the Adobe Suite a few years ago - mainly because of the integration between everything and Photoshop/After Effects.

I'm not sure if FC ever adopted CUDA processing, but Premiere allows you to allot x CUDA cores that will be dedicated to Premiere while its running. This makes rendering much quicker and improves live previews in most Adobe products. My main question is: Will dual cards allow me to utilize the CUDA's of both cards at the same time? Or does a second card just function as an alternate for additional processes?

 

[rwillett]

AFAIK FCP doesn't use CUDA.

I benchmarked a GTX660 and an older 5770 using FCPX and the older 5770 was 2.5x faster.

Rob.

 

[Dnk_Productions]

Did you ever receive an answer for this. I am using a GTX670 for FCPX and would like a performance boost. What I have read is that you don't see a boost using dual graphics card...even though the new mac pros use dual and I know that FCPX has the potential to.