CPU Scaling and Performance

CPU utilization results.
You can click on the thumbnails below for a full view of individual core/thread utilization.

AMD Athlon II X2 265

AMD Athlon II X4 645

Intel Core i7 2600K

Intel Core i7 920

AMD FX-4100

AMD FX-6120

AMD FX-8150

AMD Phenom II X2 560

AMD Phenom II X4 980

AMD Phenom II X6 1100T

Things to take into account here is that 46% of the AMD FX-8150 was utilized in our test, while the Core i7-2600K only reached 34%. Even the old and much lower clocked Core i7-920 only reached 40%. Meanwhile the AMD FX-6120 and Phenom II X6 1100T featured virtually the same CPU utilization result. Another interesting stat is that the Phenom II X4 980, Athlon II X4 645 and FX-4100 also had roughly the same utilization of ~70%.

Finally the dual-core processors were maxed out, as the Phenom II X2 560 and Athlon II X2 265 both reached over 90% utilization and constantly hit 100% when testing.

CPU Clock Speed Scaling

Before we discuss the individual CPU performance tests, let’s just take a quick look at how the AMD FX-4100 processor scales when testing between 2GHz and 4GHz. When paired with the single-GPU GeForce GTX 580 the average frame rate goes almost untouched. This suggests to us that Battlefield 3 is not very CPU demanding, at least not enough to max out a quad-core processor, which is precisely what the CPU utilization data above suggested.

The minimum frame rate does improve as clock speeds are steadily ramped up. At 2GHz we saw 63fps which was eventually increased to 68fps at 4GHz, a relatively small 8% increase for a 100% increase in operating frequency.

First we tested at 1680x1050 using the high quality setting, which means MSAA was disabled to avoid a GPU bottleneck. Almost all CPUs allowed the GeForce GTX 580 to spit out an average of 81fps, with the AMD A6-3650 and Athlon II X2 265 being the only exceptions along with our hypothetical dual-core Bulldozer processor.

At the top of our chart was the Core i7-2600K with 83fps, followed by the Core i5-2500K with 82fps. The minimum frame rates were also consistent with most CPUs averaging ~64 – 65fps.

Now at 1920x1200 all CPUs average between 66 – 68fps, while the minimum frame rate for the most part varies between 51 – 54fps. The only processor tested that dropped behind was the Athlon II X2 265, which dipped to 43fps when measuring the minimum frame rate.