Undervolting Your Phenom II And Core 2 Processors

PCMark Power And Efficiency

We tracked down PCMark Vantage performance and power consumption numbers for the default and the optimized voltage settings for both the AMD and the Intel system.

Average Power During PCMark Vantage

In the case of the Phenom II X4 955 system, the average system power requirement could be lowered from 157 to 141 W, which is a 10.2% improvement. The Core 2 Extreme QX9650 system went from 135 W to 117 W, which is an impressive result considering the processing power, which is superior to the AMD top model we used. Intel reeled in a 13.1% savings in average system power.

Total Power Used for PCMark Vantage Run

Consequently, the total power used (in watt-hours) went down as well: there was a 11.4% improvement for the AMD machine and 12.4% power savings on the Intel system. Bravo!

Efficiency (Performance per Watt) for PCMark Vantage

Finally, we related the PCMark Vantage scores to the average power the systems required (score per watt). Keep in mind that performance is exactly the same on the two machines—the only parameter we changed was processor voltage. AMD’s Phenom II X4 955 reached a 11.6% improvement in power efficiency when using PCMark Vantage as the benchmark. The Intel system advanced in terms of efficiency by 13.8%.