Total Utilization Analysis
Since our 20 games are very different when it comes to CPU/GPU utilization and dependency, we have to be very cautious when drawing any conclusions. No single answer can be applied to all games.
Take Alien vs. Predator as an example. You can easily play it with a weak CPU and a strong graphics card. But using Grand Theft Auto 4 EFLC with a setup like that would severely limit frame rates, since it's so CPU-heavy. And while budget hardware can hit more than 60 FPS in old games without breaking a sweat, the DirectX 11-class Metro 2033 and S.T.A.L.K.E.R. titles are unplayable without a good graphics card.
There are a few things you can take away from these graphs. Even if a single-core CPU is only 88% utilized, you are still missing out on about 30% of your potential graphics card performance. With a dual-core CPU, the untapped potential is just 9%, and a quad-core CPU can bring this number down to around 5%. It's important to note that multi-core CPUs decrease the jerky gameplay you might suffer on a single-core system when games need to load new resources. In any case, all four cores are very rarely fully used, leaving software with some breathing room.
In this overview, all results from the different benchmarks are added up without weighting. All values are in frames per second. We decided to not convert them to percentages, since the results tend to point towards dual-core CPUs, although most new purchases will likely be CPUs with at least three or four cores. As you can see, the performance gains from overclocking the CPU are almost non-existent at these high graphic quality settings, the 1920x1200 resolution, and with a GeForce GTX 460.