I go into testing having no idea how a dual-GPU card will perform. With a little research, I find that the card is basically set up like Crossfire or SLI, with the controller hardwired into the card rather than software. So I guess I expected performance similar to what I had with Crossfire, generally 25% to 75% increase in FPS, depending on the application. Though I really couldn't find a lot of information, I assume that the two GPUs are also like Crossfire in that one is the master and the other is the slave. That lowers my expectation of experiencing some antialiasing goodness, as I was disappointed in my AA experience with Crossfire.
I will be comparing the Asus EAH3850 X2 with two other cards, an Asus EN9800GTX Top, and an Apollo Radeon HD 3850. I thought it would be interesting to see how the pair of GPUs compares to an upper end single GPU, and how much performance improvement we get from a pair of 3850s as opposed to one.
Asus EN9800GTX Top-this factory overclocked 9800GTX is the flagship of Asus' single GPU video cards. It is a very strong performer, and totally blew away all mid-range video cards in my testing.
Apollo Radeon HD 3850 512MB-I was pleased with the performance of this card, near 8800GTX performance at about $100 less. It blew away the nVidia 8600GTS and 8600GT, and performed about the same as a factory overclocked 1GB 9800GT.
PCMark05-I first benchmarked the cards with the Graphics test on PCMark05. It is rather old, but still has some relevant tests for a modern video card.
The results here really surprised me. Maybe PCMark05 doesn't understand multiple GPUs. I know some changes were made by Futuremark to 3DMark06 to accommodate multiple GPUs. I have no idea, but I ran this test several times with the same results. I hoped further testing didn't show the same results.
3DMark06-Next I used the old faithful benchmark. I have watched this so many times I know every frame by heart. Though I still get off on the minigun.
These results surprised me more than the last. The X2 outperforming the 9800GTX was really a shocker!
3DMark Vantage-the last artificial benchmark was Futuremark's latest, actually testing the latest processes and DX10. Surely we'll see more predictable numbers here, with these three DX10 capable cards.
Yes, that's more like what I expected. So what are the findings from these results? I'm guessing that the EAH3850 X2 will perform differently with different games, and the results will not be predictable. Enough of artificial benchmarks, on with the real thing.