- Jun 8, 2013
- 1,014
- 2
- 19,365
Hi. I've had a sapphire 7950 flex for about 2 months now and decided to try and Crossfire it up with a second one.
Ordered another 7950 flex and it came defective from newegg so I RMA'd it and got a replacement that worked.
I have an Alienware Aurora with a micro ATX motherboard with almost no space between the 2 PCIx16 slots. I also had to pay someone to rewire it so that the second cards fans would not be pressed up against the assortment of wires at the bottom.
Anyway, I popped in the second card, enabled crossfire and frame pacing was turned on. At first I was getting disastrous temps on the top card. When I saw it hit 95 degrees after 5 minutes of Tomb Raider I turned off the game. Read a post where someone mentioned they had this issue so they made the bottom card drive the monitor and the top card the secondary. I tried it and it worked. Since the bottom card was like 20 degrees cooler when I had the top card driving the monitor I guess it works out better this way. With only one PCI fan I had one card at about 65 degrees and the other at around 74-80. Still high but much better than 95. I think if I got a better case with lots of fans and a motherboard with more space between the 1st and 2nd PCI slots it would be a lot better. So that's it about the heat.
Now for the performance part. I'm not seeing much improvement in performance in most of my games. Many of the games display the same FPS as they did with only one 7950. There are some areas where I get a little more FPS but that's about it.
Only Tomb Raider showed a drastic boost in performance. In Tomb Raider, with max settings and 4XSSAA I was hovering around 60fps.
I ran 3Dmark11 with one card and crossfire. Here are the results.
Single-GPU results...
Score-P7325
Graphics Score-8116
Physics Score- 5788
Combined Score- 5502
Dual-Card Score...
P10270
Graphics Score-14474
Physics Score- 5855
Combined Score-5018
So going from 1 to 2 GPU's my boosted my graphics score by a lot but my physics/combined scores were even lower than with the 1 GPU.
I'm assuming this means that my not overclocked i7 920 is too slow to keep up with the 7950s and that is why I'm not seeing any performance gains in most of my games? Also, I'm running at 1080p on a 24inch monitor.
Ordered another 7950 flex and it came defective from newegg so I RMA'd it and got a replacement that worked.
I have an Alienware Aurora with a micro ATX motherboard with almost no space between the 2 PCIx16 slots. I also had to pay someone to rewire it so that the second cards fans would not be pressed up against the assortment of wires at the bottom.
Anyway, I popped in the second card, enabled crossfire and frame pacing was turned on. At first I was getting disastrous temps on the top card. When I saw it hit 95 degrees after 5 minutes of Tomb Raider I turned off the game. Read a post where someone mentioned they had this issue so they made the bottom card drive the monitor and the top card the secondary. I tried it and it worked. Since the bottom card was like 20 degrees cooler when I had the top card driving the monitor I guess it works out better this way. With only one PCI fan I had one card at about 65 degrees and the other at around 74-80. Still high but much better than 95. I think if I got a better case with lots of fans and a motherboard with more space between the 1st and 2nd PCI slots it would be a lot better. So that's it about the heat.
Now for the performance part. I'm not seeing much improvement in performance in most of my games. Many of the games display the same FPS as they did with only one 7950. There are some areas where I get a little more FPS but that's about it.
Only Tomb Raider showed a drastic boost in performance. In Tomb Raider, with max settings and 4XSSAA I was hovering around 60fps.
I ran 3Dmark11 with one card and crossfire. Here are the results.
Single-GPU results...
Score-P7325
Graphics Score-8116
Physics Score- 5788
Combined Score- 5502
Dual-Card Score...
P10270
Graphics Score-14474
Physics Score- 5855
Combined Score-5018
So going from 1 to 2 GPU's my boosted my graphics score by a lot but my physics/combined scores were even lower than with the 1 GPU.
I'm assuming this means that my not overclocked i7 920 is too slow to keep up with the 7950s and that is why I'm not seeing any performance gains in most of my games? Also, I'm running at 1080p on a 24inch monitor.
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