As promised, we'll sum up our results with one of our nifty value scatter plots. Our overall performance number comes from the geometric mean of all tests. We've converted the 99th percentile frame times into their FPS equivalents for the sake of readability. The pricing for the current CPUs comes from official Intel and AMD price lists. The legacy chips—specifically the Core i5-655K, i5-760, and i7-875K processors—are shown at their original introductory prices.
As usual, the most desirable positions on the plot are closer to its top left corner, where the best combinations of price and performance can be found.
As you probably expected, the Ivy Bridge-derived processors are near the top in overall gaming performance. Intel has made incremental improvements over the Sandy Bridge equivalents in each price range, from the i5-2400 to the i5-2500K and i7-2600K. The Core i5-3470 offers perhaps the best combination of price and performance on the plot, and the Core i5-3570K offers a little more speed for a bit more money. The value curve turns harsh from there, though. The i7-3770K doesn't offer much of an improvement over the 3750K, yet it costs over a hundred bucks more. The Core i7-3960X offers another minuscule gain over the 3770K, but the premium to get there is over $500.
Ivy Bridge moves the ball forward, but Intel made even more performance progress in the transition from the prior-generation Lynnfield 45-nm processors—such as the Core i5-760 and i7-875K—to the 32-nm Sandy Bridge chips. From Sandy to Ivy, some of the potential speed benefits of the die shrink were absorbed by the reduction of the desktop processor power envelope from 95W to 77W.
Sadly, with Bulldozer, AMD has moved in the opposite direction. The Phenom II X4 980, with four "Stars" cores at 3.7GHz, remains AMD's best gaming processor to date. The FX-8150 is slower than the Phenom II X6 1100T, and the FX-6200 trails the X4 980 by a pretty wide margin. Only the FX-4170 represents an improvement from one generation to the next, and it costs more than the Phenom II X4 850 that it outperforms. Meanwhile, all of the FX processors remain 125W parts.
We don't like pointing out AMD's struggles any more than many of you like reading about them. It's worth reiterating here that the FX processors aren't hopeless for gaming—they just perform similarly to mid-range Intel processors from two generations ago. If you want competence, they may suffice, but if you desire glassy smooth frame delivery, you'd best look elsewhere. Our sense is that AMD desperately needs to improve its per-thread performance—through IPC gains, higher clock speeds, or both—before they'll have a truly desirable CPU to offer PC gamers.
Fortunately, there are some glimmers of hope emanating from AMD. The Trinity APU, which combines higher-IPC Piledriver cores with an integrated Radeon, beat out an Ivy-based mobile CPU in our gaming tests. Trinity is slated to make its way to the desktop this fall, and it may provide some relief when it arrives. After that, we expect an eight-core chip based on Piledriver and then an APU and CPU refresh based on Steamroller, another architectural revamp. We think the firm is moving in the right direction, which is a change from recent years. Whether it can do so quickly enough to catch up with Intel, though, is the truly vexing question.
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