While we’ve often seen so-called CPU bottlenecks impeding the performance of our multi-GPU systems, today’s highest-quality gaming test has proven that when it comes to single-GPU systems, even a high-performance card like the Radeon HD 5850 can’t outstrip the capabilities of a modern low-cost CPU.
Average performance differences are small and tend to favor AMD's architecture, which, given the pricing advantages of AMD products, in turn favors mid-budget gamers. Better news for AMD buyers is that even-cheaper Athlon II X3 processors offer similar gaming performance compared to today’s tested Phenom II X3 720, although using one would have prevented us from price-matching today’s configurations.
Moderately lower gaming value won’t prevent some users from buying a Core i3-, i5-, or i7-series processor for Intel’s superiority in many non-gaming applications. The good news for low-budget Intel buyers is that jumping in with the cheapest i3 model yields virtually no performance deficit at the highest gaming details, at least when the system is limited to a single high-end, single-GPU card like the Radeon HD 5850.
Some readers will argue that today’s tests are an exception, that most mid-market builders won’t automatically shoot for the highest gaming details and that most of our own tests have been performed at lower-detail levels that led to far different conclusions. The counterclaim for today’s analysis is that anyone who spends over $300 on a high-end graphics card should expect to be able to play at these high settings and that, with the exception of Crysis, today’s full-detail game settings are completely playable at 2560x1600. Four of today’s titles could even support smooth gameplay at those super-high resolutions and detail settings with AA enabled.
Yet we did approach the limits of playability a few times, and some users are certain to exceed those limits by pushing resolutions even higher with ATI Eyefinity triple-monitor configurations. Having already reached the limits of our graphics card, this can’t be fixed by using a faster processor. Those users will instead be forced to reduce detail levels in exchange for increased pixel counts, but those added pixels still place the bottleneck at the GPU, rather than at the CPU, and a faster processor simply won’t be beneficial.
To push the need for a better processor, it is necessary to go beyond the capabilities of a single GPU and into the realm of CrossFire or SLI. When cost is of the utmost concern, this isn't particularly likely. So, our tests prove that a low-cost CPU will do the job just as well as a high-priced part.