First post, by asdf53
Socket A systems have a reputation as power hogs, but what about newer motherboards that can manipulate clock speed and voltages? Does it help or will the CPU fail to work at the slightest undervolt? I connected an ampere meter to the PSU to measure total power consumption of the system and did some testing.
System: MSI K7N2 Delta-L (nForce2), Athlon XP 2700+ (Thoroughbred), Geforce 2 MX, 400W IT-Power PSU
I started with a clock speed of 1950 MHz and gradually decreased the core voltage to see how it impacts the power consumption. For testing I used prime95 to get the CPU to 100% load.
1950 MHz @ 1.65v: 132w load / 94w idle
1950 MHz @ 1.6v: 124w / 89w
1950 MHz @ 1.55v: 119w / 85w
1950 MHz @ 1.50v: 116w / 83w
1950 MHz @ 1.42v: 107w / 79w
1950 MHz @ 1.3v: fails to POST
Now for the most interesting part: What is the lowest power consumption we can achieve? I set the clock speed and core voltage to the lowest values that the board supports:
700 MHz @ 1.3v: 70w / 61w
Then I tried to find the sweet spot, the highest clock speed that's still stable at the lowest voltage of 1.3v:
1750 MHz @ 1.3v: 86w / 63w
That's 200 MHz slower than my usual system, but draws 46w / 31w less power. That's pretty good! What are some of your results? Does anyone have a board that can go lower than 1.3v?