How much does the on-die L2 cache on a modern CPU (Athlon XP, Pentium 4) contribute to the total power usage of the CPU? I’ve heard conflicting information; some people claim it’s the most power-hungry component on the CPU, with others saying it uses very little power, compared to the rest of the CPU.
I’ve done some research, and the power usage of an AMD Duron 1.3Ghz with 64KB of L2 cache is 60W, the same as an Athlon XP 1500+ 1333Mhz with 256KB L2 cache. The cores are otherwise identical. On the other hand, The AMD Athlon XP 2700+ at 2167Mhz with 256KB L2 sucks down 68.3W, while the XP XP 3000+ at 2167Mhz with 512KB L2 uses 74.3W. Though, the XP3000+ uses a somewhat tweaked core.