A preview of Hydra performance
Below are the performance results we managed to squeeze out of the Hydra during our session in Lucid's offices. Going on-site like this to conduct testing is never our preferred situation, and as one would expect, we were limited by time and circumstance in various ways. We had to choose quickly from a limited selection of games, to limit the number of repetitions in our test runs (we tried to do two for each test, if possible), and to test with the hardware Lucid made available to us.
Still, we had time to test a handful of games on a number of different GPU configs. We even got a preview of the Hydra's mixed-vendor capability by pairing a GeForce GTX 260 with a couple of different Radeons.
The PC we used for testing was based on a Core i7-920, a Gigabyte EX58-UD3R motherboard, and the 32-bit version of Windows 7. Oddly, the system had only two 1GB DIMMs installed, so one of the Core i7-920's memory channels wasn't available. In fact, when we first started testing, only 1GB of memory was available, because the second DIMM was installed in the wrong slotan artifact of the limited setup time Lucid had for this press demo. We corrected that problem, though, and moved on with our testing with the full 2GB at our disposal.
The first game we'll look at is Operation Flashpoint: Dragon Rising. We used FRAPS to record frame rates in this game and in FEAR 2, and to keep things very repeatable, we simply stood still at a fixed point in the game and recorded frame rates for 30 seconds. That's not how we usually test, but it should suffice for our purposes here. Also, all of the multi-GPU configurations below make use of the Hydra for load balancing. We didn't have the chance to test with CrossFire or SLI for comparison.
In this game, the Hydra delivers performance scaling in earnest, even with asymmetrical and mixed-vendor configurations. No, we're not seeing linear performance scaling when, say, going from a single GeForce GTX 260 to two of them, but I doubt this game is entirely GPU-limited at this resolution.
Surprisingly, the mixed-mode config with a GeForce GTX 260 and a Radeon HD 4770 outperforms dual GTX 260s. That's unexpected, but otherwise, the Hydra's performance is pretty much as advertised.
As I noted before, we did run into visual corruption problems with the 4890+4770 config in the two DX9 games, Operation Flashpoint: Dragon Rising and FEAR 2. We've reported the performance results anyhow, for the sake of completeness, but they come with that caveat.
The visible problems of the 4890+4770 config translate into performance issues here, as the pair of GPUs turns out to be slower than a single 4890. Otherwise, though, the Hydra does its thing quite well.
These last two benchmarks use DirectX 10, and as I mentioned, the mixed-mode configs with DX10 apps had much darker displays than normal, for whatever reason. They looked fine otherwise, though, and the performance scaling pictures for these two DX10 apps are very similar. Generally, the Hydra achieves good results once again, although the 4890+4770 pair's scaling issues remain.