Power Consumption: Athlon 64 vs. Athlon 64 X2

In Part II of our preview of Intel's dual core processors, we noted that the addition of a second CPU core generally didn't increase overall system power consumption by that much. In fact, the Pentium D 2.8GHz vs. single core 2.8GHz comparison yielded only a 15% increase in system power consumption under load for the dual core CPU. While we didn't look at power consumption in our dual core Opteron review, armed with desktop parts, we were ready to look at how desktop power consumption was affected by the move to dual core.

Single core AMD CPUs have always consumed less power than single core Intel chips; in fact, the 130nm Athlon 64 FX-55 consumes less power than a 3.0GHz Pentium 4 (5xx or 6xx series).

How much more power would a dual core Athlon 64 X2 consume? To answer this question, we looked at three CPUs on the same platform and measured system power consumption. We used a 130nm Athlon 64, a 90nm Athlon 64 and a 90nm dual core Athlon 64 X2 - all clocked at the same frequency and with the same per-core cache sizes. The results are below:

AMD Single Core vs. Dual Core Power Consumption

At idle, the Athlon 64 X2 falls directly between the 90nm Athlon 64 and the 130nm Athlon 64, but does the same hold true when the system is fully loaded performing our WMV HD encode test?

AMD Single Core vs. Dual Core Power Consumption

Surprisingly enough, it is. Clock for clock, the Athlon 64 X2 will consume less power than a 130nm Athlon 64, and less than 20% more power than a 90nm Athlon 64. Note that the Athlon 64 X2 4200+ compared here also consumes less power than all single core 90nm Intel Pentium 4 CPUs. Even the Athlon 64 X2 4800+ consumes less power than all single core 90nm Pentium 4 CPUs.

If you're worried about the Athlon 64 X2 generating too much heat, there's no reason to be concerned - if you're happy with the heat levels of your current 130nm Athlon 64, the X2 will run even cooler.

Index Business/General Use Performance
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  • xsilver - Monday, May 9, 2005 - link

    #33 ..agreed..
    If anything I think AT is more biased towards AMD, not intel

    and #32, there is a well known fact that in scientific testing, if you already have a bias towards one outcome (read: amd fanboi) then your results will subconciously show what you set out to say.... that's why in real scientific tests, also known as a "double blind" test, the testers dont know what they are testing and the subejects dont know what they are using ....in this case the subjects are the cpu's so they cant talk :P
  • wien - Monday, May 9, 2005 - link

    #32 Wow... just. wow.
  • crisagatie - Monday, May 9, 2005 - link

    This is another Inteltech bullshit. After X2 beating Intel hands down in all tests and benchmarks, these guys put up a bag of their own tests (multitasking scenarios) toped by Intel in every single one. Then they say the results are "a mixed bag", with Intel and AMD performing equally...

    You, Anandtech guys, read the reviews all over the Internet! And try believing: Intel sucks! X2 is by far the best performer (even X2 4200+), being at the same time a cheaper option to Intel D 840 and EE.
  • Viditor - Monday, May 9, 2005 - link

    As to availability, I note from the Dell site that the EE 840 isn't available till June 15th either...

    For applications, I noted in Tech Report's review that they did some very good graphs illustrating results on a thread-basis, and they included the dual Xeon 3.4GHz. It appears that for rendering workstations, the 4800+ blows the doors off of the dual Xeon, at a fraction of the price...
    This just caused me to contact a friend who put a big hold on 12 new workstations he was ordering!
  • Samus - Monday, May 9, 2005 - link

    Anand, did you happen to do any overclocking with the X2? If so, were the results simular to typical single-core 90nm?

    I'm sure there is some headroom and 2.6GHz can be achieved with the X2, which would make it untouchable if it scales accordingly.
  • Zebo - Monday, May 9, 2005 - link

    #20 dude uncool. there is kids here besides I could'nt fiqure out your point anyway? Did you hate it or love it?
  • phaxmohdem - Monday, May 9, 2005 - link

    #27 your dead wrong.....

    I"m a f*cking idiot :)
  • RadeonGuy - Monday, May 9, 2005 - link

    #20 your a idiot
  • DeftNinja - Monday, May 9, 2005 - link

    ^ Probably because you are a cunt.
  • AnandThenMan - Monday, May 9, 2005 - link

    Scratch my comments about no power consumption tests. How did I miss them? *scratches head* ?????

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