If you're a regular Tom's Hardware reader, a performance evaluation like this is par for the course. If you're new here, your head is probably spinning after seeing all of those bar and line charts, along with the talk of scaling, bottlenecks, and code paths. Let's break it all down though, piece by piece.
We'll start with graphics--specifically, the fact that Cataclysm includes support for DirectX 11. It's still not clear exactly what Blizzard did to optimize this particular code path, but enabling DX11 support on a platform with a compatible graphics card has the potential to enable significant performance gains on both AMD- and Nvidia-based boards. There's a catch, though. In order to realize those gains, you can't be limited by the graphics card's performance. That means you need a fast enough GPU to be platform-bound. As resolution increases, applying more of a GPU load, the increase attributable to DX11 tends to drop. With that said, I have friends running mainstream processors and mainstream GPUs who've seen 20 FPS boosts at 1920x1080 using the Ultra quality preset. Turn it on if you have a compatible card!
That takes us to the perpetual back and forth between AMD and Nvidia. Although AMD's Radeon HD 5800- and 6800-series cards demonstrate notable differentiation at 2560x1600, lower resolutions show the company's fastest boards running into a limitation in the mid-80 FPS range--below Nvidia's competing GeForce GTX 460. The high-end Nvidia cards start hitting their own platform-imposed ceilings up above 100 FPS. There's really no good explanation for this other than AMD's cards are more platform-dependent than Nvidia's in this game. Once you dip below GeForce GTX 460 levels, there's a huge drop-off to the GTS 450 and GTx 200-series cards. At the point, AMD's offerings become more competitive, with the Radeon HD 6850 and 5770 looking like particularly solid values for the folks who want in on Ultra quality settings without spending a ton of money.
And how about processors? After all, games are impacted most forcefully by the power of your GPU. WoW, it appears, bucks that trend to a large degree. Without question, we see the best performance on Intel CPUs with remarkable scaling from 100 FPS down to 60ish frames per second with a GeForce GTX 480 at 1680x1050 (Ultra quality) as you shed clock rate, cores, and cache. We've said it before and we'll say it again: when it comes to gaming, balance is everything. Don't buy a high-end graphics card if you're using a mid-ranged processor; you'll simply handicap the GPU, failing to realize its potential. In this case, an overclocked Core i5 serves up reasonable performance, but a Core i7 is undoubtedly the gold standard if you're rocking a fancy graphics card.
That's not to say you can't get playable frame rates from a processor from AMD. But wow--they turn in significantly lower average frame rates in Cataclysm. Like, even the fastest unreleased six-core CPU gets pegged at 60 FPS with a GeForce GTX 480 under the hood. Thinking the problem could have been with our graphics card, we even swapped in a Radeon HD 5870 and saw the same ceiling at 59 frames per second. You can get more performance for about $150 less from a dual-core Core i3-530. Sad.
With all of that said, it's safe to say that Blizzard effectively gave its Cataclysm expansion a healthy injection of eye candy without making the game inaccessible. It's still very much playable the way its developers intended with mid-range graphics and processors. Now, if you'll excuse me, it's time to dial-in my own optimized settings before my digital download goes live at midnight!