AMD Phenom: Up to 27 Watts During Standby
Before we get to the comparison tests of all the AMD processors, we would like to talk about a problem with the Phenom processor. During our testing, we found out that, in comparison to all other AMD CPUs, the Phenom has a very high power draw during standby. Even when Cool’n’Quiet mode is activated, depending on which motherboard is used, the energy intake is almost three times higher.
The Phenom 9600 processor switches down to a clock rate of 1150 MHz during standby mode. Its multiplier then becomes 5.8x and the core voltage goes down to 1.050 V.
In order to find out where the processor’s high power intake comes from, we measured our Phenom 9600 Black Edition on AMD 790FX boards from Asus, Gigabyte and MSI.
In our opinion, the electrical intakes of all three motherboards are too high to be acceptable. We measured 27.69 W on the Gigabyte board, while the MSI board achieved 20.27 W, which at its best is twice as much as the Athlon 64 X2 6400+.
Surprisingly, there is a difference of up to 7.4 W between the MSI and Gigabyte motherboards. While the MSI motherboard has a 5-phase regulator and the Gigabyte board is equipped with a 10-phase regulator, it’s unlikely that the Gigabyte’s additional 5-phase regulator uses more than 7.4 watts. There is the possibility that the Phenom doesn’t switch down to a lower voltage properly, which cannot be detected with classic diagnostic tools like CPU-Z, Core-Temp or Everest.
The Phenom 9600 needs up to 20.27 watts during standby, even with Cool’n’Quiet mode turned on. With the Gigabyte board it even goes up to 27.69 W. When compared to the Athlon 64 X2 6400+, the electrical intake is simply too high.