Power-draw and overclocking
| Power consumption - idle | ||||||||
|---|---|---|---|---|---|---|---|---|
| AMD Phenom II X4 940 BE | AMD Phenom II X3 720 BE | Intel Core 2 Quad Q8200 | Intel Core i7 920 | Intel Core 2 Duo E8400 | AMD Phenom II X4 810 | AMD Phenom X4 9950 BE | Intel Core 2 Quad Q9300 | AMD Phenom II X4 920 |
| 123 | 124 | 115 | 147 | 110 | 123 | 132 | 115 | 120 |
Idle and load power-draw is measured at the mains, via a watt-meter.
The idle figure represents the system simply running Vista with no other load imposed, and the horde of processors had their respective energy-saving technologies - Cool 'n' Quiet and EIST - turned on.
We don't see too much variation between the chips, run on three platforms, and the only standout figure is the 147W for the Core i7 system, although it does use more RAM.
| Power consumption - load (2D) | ||||||||
|---|---|---|---|---|---|---|---|---|
| AMD Phenom II X4 940 BE | AMD Phenom II X3 720 BE | Intel Core 2 Quad Q8200 | Intel Core i7 920 | Intel Core 2 Duo E8400 | AMD Phenom II X4 810 | AMD Phenom X4 9950 BE | Intel Core 2 Quad Q9300 | AMD Phenom II X4 920 |
| 201 | 176 | 153 | 255 | 140 | 178 | 229 | 155 | 195 |
Load is defined as running wPrime 1024M calculation which stresses all the cores.
Crank it up and the X4 810 and X4 720 BE are pretty frugal customers
Overclocking
Testing of the X4 920 and X4 940 Phenom IIs showed us that AMD had significant frequency headroom on its 45nm process. Knowing that X4 810 is clocked in at 2.6GHz and X3 720 BE at 2.8GHz, overclocking yielded the following results when using a basic AKASA AK-876 cooler and conservative settings of 1.5V for the CPU:
X4 810 - 3.39GHz. Our sample wouldn't boot at higher than 3.4GHz with 1.55V.
X3 720 BE - 3.51GHz with 1.5V and 3.61GHz with 1.55V
Clearly, there's frequency room to spare on both chips, so we should see faster speed-grades released in the next few months, and it's all the more galling that a X4 3.2GHz FX part wasn't introduced at this time; we're sure that AMD can yield that high.
