Benchmark Results: Battlefield 3 And DiRT 3
Is the new system CPU-limited in Battlefield 3? Actually, 200 FPS is this game's ceiling. Unfortunately, the frame rate cap is going to affect this quarter's overall average performance score (higher benchmark numbers would have extended the lead of our dual-Radeon HD 7970 system in gaming).
As we increase the detail levels and resolution in Battlefield 3, frame rates come down away from the cap. Most amazing, perhaps, is the drop that happens between 1920x1080 and 2560x1600. Performance remains playable, but a slide from 170 average frames per second down to 52 on our overclocked configuration is certainly extreme.
We aren't aware of an artificial frame rate limit in DiRT 3, so we're more likely to attribute similar performance to a platform-oriented bottleneck. This time, we're thinking it's memory speed, though. After first recording 170 FPS at several resolutions, we enabled the memory kit's XMP profile and watched the frame rate jump to 190 FPS.
Although we're fairly confident that our bottleneck was memory performance at the lower detail settings, we know from lots of experience testing this game that the grouping tightens at more graphically-demanding settings on AMD GPUs. The spread is typically tighter still when using two AMD-based cards in CrossFire. Historically, we've chalked this up to processing overhead associated with the multi-GPU rendering technology, but in light of our earlier discovery, we think we have an interesting benchmark to run in an upcoming memory story, too.