CrossFireX Arrives: First Look at 3 and 4 GPUs in 2 Card Setups

The Test

This time around, we had the opportunity to compare games of our choosing. We did check to see if there were any real performance improvements up from our preview, but we haven't seen any huge changes. Crysis still only shows a performance improvement with two GPUs, and adding a third or fourth can sometimes even degrade performance. That's unfortunate, considering Crysis remains one of the games best able to bring any current GPU setup to its knees.

We decided to tackle this article from the perspective of two-card performance that enables three or four GPUs. This means using the 3870X2 in combination with the 3870 or another 3870X2. There are quite a few permutations that AMD's CrossFireX makes possible. With the way the industry is moving, it seems we won't be able to avoid further investigation into more-than-two GPU configurations. We will definitely continue to investigate this and will report on any interesting findings, but for now we will use two-card setups in order to avoid any concerns about PCI-E slot bandwidth playing a part in our initial performance numbers.

Our goal is to do two things. First, as in our preview, we want to assess the additional benefit gained from going to three or four GPUs. This is obviously relevant, as we want our readers to know what they are getting for their investment. Second, we want to compare the performance of the 3870 in its multiple configurations to other competing solutions from NVIDIA. This will help us to put the performance in a context of relative value to other single and dual card options.

Our test system is Intel's Skulltrail, as it has been in the recent past for graphics articles. We have moved off the AMD Phenom system and will now be able to better compare relative performance values on the best platform to do so. Here is our test setup:

Crysis Performance

As one of the most demanding titles currently available, Crysis seems like a great showcase for multi-GPU technologies. We did test performance, but with the current drivers we saw no improvement in performance. However, we also tested prior to the 1.2 patch that just came out on Thursday. We will look at Crysis performance in a future update once we have conducted additional testing.