System Builder Marathon, Dec. 2011: $2400 Performance PC

Power, Heat, And Efficiency

Liquid cooling usually drops temperatures, though sharing a small radiator with the GPU doesn’t help our CPU temperatures compared to the previous machine.

Efficiency compares work to energy, so we first compile a performance chart to gauge work per unit of time in comparison to the previous system’s baseline. After this, we compare the performance ranking to the power ranking.

The current overclocked PC is around 9% faster in games than its tweaked predecessor, but it also consumes more than 9% additional power. Keeping the former system’s standard speed as our baseline, we calculate our efficiency chart around it. Since the baseline is 100% (and yet nothing is 100% efficient), we then subtract 100% from the efficiency chart results to show only how much more or less efficient each system is by comparison.

First calculating overall performance at 10% for storage performance and 30% each for Gaming, Encoding, and Productivity scores, our power-per-performance chart shows that the previous build was more efficient in spite of its lower performance. Overclocking boosted its efficiency by increasing performance by more than power consumption.

A big boost in CPU voltage required by the new system increased its power consumption by a greater percentage than performance, resulting in less efficiency.

Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.