Testing: Synthetic Benchmarks
We started our data crunching with Cinebench, a simple synthetic benchmark developed by Maxon to measure a PC's processing power. The test renders a complex 3D scene, and puts all of a processor's available cores to task, with support for up to 64 cores. The i7-3960X and i7-990X are 6-core CPUs, for a total of 12 threads, care of Intel's hyperthreading technology. The Core i7-2600K offers 4 cores, for a total of 8 threads.
Once the scene is rendered, Cinebench assigns a score--higher is better. The results in our runs were fairly straightforward. The i7-3690X earned 10.53 points, the i7-990X earned 7.27 points, and the i7-2600K earned 6.97 points. Cinebench's test runs faster with more cores at its disposal, so the superiority of the Extreme Edition parts is to be expected. Of particular interest is the relatively small gap between the Core i7-990X and the Core i7-2600K. That's the Sandy Bridge effect--the 990X is built on Intel's Clarkdale architecture, which launched back in 2010. What a difference a year makes, eh?
Next we ran PCMark 7's Productivity test, which measures a machine's performance in a few multitasking and generic office application workloads. Once the test is complete, PC Mark 7 outputs a Productivity score. The Core i7-3960X earned a score of 2487, the Core i7-990X a score of 1947, and the Core i7-2600K a score of 2327. This lineup--Sandy Bridge up front, Clarkdale trailing--proved to be a recurring theme as we moved into testing that focused on the power of each core, and not necessarily a multitude of them.
Finally, we tested with Unigine Heaven, a DirectX 11-based benchmark built on a game engine that is currently in development. Though its results aren't directly comparable to real-world gaming, it does provide a good idea of how the different processors stack up, and what you could may encounter later in the life of your machine. Here is a chart of our Unigine Heaven benchmark results.
The results here were close--for the Core i7-990X and Core i7-2600K, at least. Evidently the architecture changes between Clarkdale and Sandy Bridge have yielded to some significant performance gains. Of particular relevance to gamers, the results indicate that throwing more cores at games doesn't necessarily produce superior performance. We'll see more evidence supporting that conclusion when we look at the results of our proper games tests.