35 AMD CPUs Tested for Power Consumption

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Energy Loss: When Cool’n’Quiet Mode Doesn’t Work

Sometimes it is not possible to get the processor to go into Cool’n’Quiet mode while in standby. This may be due to an error in the BIOS, the operating system malfunctioning, or the motherboard crashing during the attempt; in some cases, the reason is unknown. Sometimes the dynamic down-switching of the CPU will interfere with active programs, so the user is forced to turn the economy mode off.

35 amd cpus

The BE processors have, at 3.2 W, the lowest energy loss, because their normal clock rate’s energy consumption is low. The Sempron 64 processors have to deal with 5.1 to 6.6 watts of energy loss. The energy efficient processors, while not in Cool’n’Quiet mode, have an energy loss of 5.2 to 10.7 W. The classic Athlon 64 models do the worst: the high energy-intake without Cool’n’Quiet mode is between 11.4 and 21.8 watts.

The Phenom does well, with about 8 W of energy loss, but when combined with the high intake it has during standby, it becomes 20 W—twice as much as any other CPU model.

Bert Toepelt
22 Comments Comment from the forums
  • Excellent article! It would be nice to see similar article for Intel processors because even if they are less power hungry, the Intel chipsets are not the "greenest". I am just considering a 24/7 home server and this information is very useful for me. Thank you!
    Reply
  • Good article! You have the wrong processor name listed for the 2.10 GHz G1 Brisbane as "Athlon 64 X2 4800+ EE". It should be 4000+. I was a bit confused when I read the performance charts and noticed two 4800+ listed until I realized the mistake.
    Reply
  • zenmaster
    I was glad to see you got some of the new 45w AMD Chips in there.
    Reply
  • xoham
    Intel is not the greenest if it is less power hungry? Do they not meet RoHS standard or something?
    Reply
  • zenmaster
    He said the "Intel Chipsets" are not the greenest.
    The are still built on the 90nm process.

    The P45 will introduce the 65nm process on the chipsets.
    The latest AMD Chipsets use the 55nm process.

    In regards to CPUs, The Intel CPUs generally use less than the AMD CPUs.
    He was simply pointing out that the CPUs lose some of the benefeit of their low power consumption due to the chipset.

    For lower-end chips sitting idle, the difference in power usage of the chipsets can be significant. If you are looking at a higher-end chip under load, the power usage of the chipset becomes nominal.
    Reply
  • einheriar
    besides that intel still has the memory controller as a separate chip on the motherboard, where as amd has that included on the chip.. therefor a higher chip power use might be offset by the absence of the external memory controller, which would become visible when idling ..
    Reply
  • so my x2 4000 ee (in tables interpreted as one of 4800's - due mistake) isn't so bad after all, I don't care about 2w/hour, when I have 24" lcd :-)
    Reply
  • Mathos
    The extra power consumption on the Phenom is due to the fact that the NB/IMC voltage stays at 1.250v even when the rest of the processor is running in standby. Kinda of annoying that they put it that high, since with a bios that still has the p-states section you can easily under volt the IMC without losing stability, especially at stock speeds. That will cut down on the idle and load power usages drastically.
    Reply
  • royalcrown
    I like how review site all push efficiency now since AMD can't really compete on performance. Yawn.
    Reply
  • jprevost
    Bravo for a great technical article. I can't tell you guys how nice it is to see some great charts. Charts are good, and you guys are good at charts, just don't stop adding to them!
    Reply