Does anyone have any hard evidence in regards to scaling these gpu's together? I thought I had a problem with bottlenecking because of the pci-e lane but after watching the following link, I am not convinced anymore.
http://youtu.be/rSfifE2Domo
My motherboard has 4 pci-e lanes capable of x16 and work with the following configurations :
16/0/0/0
16/0/16/0
8//8/16/0
8/8/8/8
With the 6990 in slot 1(x16) and one 6970 in slot 3(x16) I get a 3dmark11 score of X4888. With the 6990 in slot one and a 6970 in slots two and three, I get a score of X4873 with one of the 6970's disabled. So this should mean that the 6990 is now in a x8 slot with that configuration. As soon as I enable the second 6970 and re-run the benchmark, I get a score of X3916. If it's not due to the lane is it a problem with scaling? I have the latest driver version installed. Does anyone know of a benchmark program that I can use that will test this setup at 5760x1080? I have noticed that in 3dmark11 none of the scores that I browsed for 3 or 4 6970's are much higher than the score I get with 3 6970's(basically a 6990 and 6970 in crossfire) When I have a bit more free time tomorrow, I will load bf3 and use fraps with different configurations to see what kind of results I get.
**edit**
All test were run with the gpu's at 830MHz and 1250MHz(gpu and memory) and my processor and ram were running at 4GHz and 1866MHz
http://youtu.be/rSfifE2Domo
My motherboard has 4 pci-e lanes capable of x16 and work with the following configurations :
16/0/0/0
16/0/16/0
8//8/16/0
8/8/8/8
With the 6990 in slot 1(x16) and one 6970 in slot 3(x16) I get a 3dmark11 score of X4888. With the 6990 in slot one and a 6970 in slots two and three, I get a score of X4873 with one of the 6970's disabled. So this should mean that the 6990 is now in a x8 slot with that configuration. As soon as I enable the second 6970 and re-run the benchmark, I get a score of X3916. If it's not due to the lane is it a problem with scaling? I have the latest driver version installed. Does anyone know of a benchmark program that I can use that will test this setup at 5760x1080? I have noticed that in 3dmark11 none of the scores that I browsed for 3 or 4 6970's are much higher than the score I get with 3 6970's(basically a 6990 and 6970 in crossfire) When I have a bit more free time tomorrow, I will load bf3 and use fraps with different configurations to see what kind of results I get.
**edit**
All test were run with the gpu's at 830MHz and 1250MHz(gpu and memory) and my processor and ram were running at 4GHz and 1866MHz