System Builder Marathon, Dec. 2009: $2,500 Performance PC

Power, Heat, And Efficiency

Our current build consumes approximately one third the idle power of our most recent high-end $2,500 build and most of that savings can probably be attributed to the updated graphics configuration. Full load power is also down significantly, making even our 850W power supply seem like overkill.

Our graphics card ran hot, as it appears ATI’s automatic fan controls are set for a peak temperature of 86 degrees Celsius. Our CPU ran nearly as hot under full load, and combining CPU and GPU loads (not shown) pushed our CPU temperatures upward by another 10 degrees.

An average performance increase of 18% combined with an average power increase of 23% yields an efficiency deficit of around 4% due to overclocking. Experience tells us that a lower-voltage overclock could have yielded an efficiency increase compared to stock settings, while a higher-voltage overclock would have made efficiency far worse.