View Full Version : Question regarding dual GPU graphics cards
Is running a dual GPU graphics card (like the GTX 295 or HD 5970) the same as running two single GPU graphics cards in SLI or CrossFireX? And, for dual GPU graphics cards, does the computer see the card as two cards in SLI or CrossFireX?
12-13-09, 02:22 PM
Mind you, I've never owned a dual-GPU card before.
That said, from all that I have read about them- they show up as though you had two cards in SLi or CrossFire. They do not show up as a single card. Meaning, go into Device Manager and under Display adapters you should see two cards listed, instead of one.
The disadvantage, that I've read of at least, is that you cannot manually disable the second GPU. With traditional SLi or CrossFire, you can disable your additional cards. With the dual GPU cards, they are always running in SLi or CrossFire. So if you happen to be playing a game that does not support CrossFire or SLi (meaning SLi or CrossFire yields lower framerates than a single card would) you're stuck.
Not sure if that's still a problem, maybe newer drivers have solved this. I'm sure some of the members that actually have experience with dual GPU cards could be a bit more helpful. :)
Thanks for your response. Can anyone else confirm what Redeemed has said? :)
12-13-09, 07:28 PM
Yeah he's correct and yes its pretty much the same thing as two separate cards. However, you are able to disable sli/cf and run the cards in single gpu mode if need be. Some do this to drive three displays on a single GTX295
Does two GTX 285 cards equal one GTX 295? Is the GTX 295 basically two GTX 285 GPUs on one card? What about the HD 5970? Also two HD 5870 GPUs on one card?
Secondly, how does cooling come into the picture? Would temps be lower for two separate cards in SLI/CrossFireX compared to one card with two GPUs on it?
12-14-09, 03:30 PM
I always thought that two separate cards would be better than a multi-GPU card, for example, 2-285s better than one 295, etc. However you have to remember you need more power for two separate cards, as well they they create more heat.
GTX295 is like two GTX260+'s with the shaders of GTX285. 5970 is like two 5870's clocked at 5850 speeds, but still with all the shader units etc.
So they both can't be compared to multi card setups.
12-15-09, 11:04 PM
Dual-gpu cards are at a slight disadvantage because of less PCI-E bandwidth. The on-board bridge isn't capable of 16x PCI-E. So in most every case you will see two separate cards best the dual-GPU card by a little.
You can disable one of the GPUs within the Catalyst by turning off Catalyst AI. This will cause you to run in single GPU mode.
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