Opening The CPU Bottleneck

What does it mean to run face-first into a bottleneck? When we talk about bottlenecks here on Tom's Hardware, we're usually referring to a single component that's preventing the rest of a PC from reaching its full performance potential in any given benchmark. For games, that component is usually either the CPU or graphics card, depending on how much performance the other part provides.

Our System Builder Marathon machines often expose CPU limits when multiple graphics processors are combined, but most gamers begin their builds with only a single GPU. Among these, AMD’s $320 Radeon HD 5850 represents the highest performance most gamers will want to spend money on. The argument, of course, is that as you start shopping for more expensive alternatives, like a $700 Radeon HD 5970, consoles start looking a lot more attractive.

With our best bang-for-the-buck graphics card fairly well defined, the question becomes: how much CPU do we need to milk the last ounce of performance from this pixel-spewing beast? Would a dual-core CPU do the job or, given that today’s games are ever-more multi-threaded, would a triple- or even quadruple-core processor be needed? How much could overclocking help? Must we spend all of the money saved on the CPU to purchase a big cooler? Knowing that all of the subsequent questions must be addressed to completely answer the first, we gathered our Intel and AMD processor samples and began testing.