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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  • Ender17 - Monday, May 9, 2005 - link

    Anand, have you tried overclocking these X2 chips?
  • AnandThenMan - Monday, May 9, 2005 - link

    Very poor (pre)review IMO. Not nearly enough multi-tasking tests, and NO overclocking tests for some strange reason. And what about power consumption tests? Observations on heat output?

    And I agree with #18, the Q3 or Q4 statement with no explanation is odd and getting annoying.

    Hothardware and Thetechreport have much better preview articles.
  • Anand Lal Shimpi - Monday, May 9, 2005 - link

    dougSF30

    AMD is playing a bit of a word game with regards to availability. When they say available in June, they mean that through select system system builders the Athlon 64 X2 will be available in June. Across the board availability (as in you'll actually be able to buy an Athlon 64 X2 CPU alone) will be Q3/Q4 - that is directly from AMD to my inbox. It's just that availability in June sounds a lot better, much like Intel saying that availability in May sounds good - both companies appear to be playing the same word game ;)

    Take care,
    Anand
  • Ahkorishaan - Monday, May 9, 2005 - link

    NIce review Anand, I've more or less chosen the 4400+ X2 as my next processor from my XP 2100+. She's getting venerable now, pushing 3 years old now.
  • phaxmohdem - Monday, May 9, 2005 - link

    I just creamed my pants. Who the F*ck wants an 820 Pentium D with you can have a freaking "X2" F*ck yeah! thats Xtreme muther F*cker!

    Its like that "America F*ck Yeah!" song from America World Police.......

    "Wal-Mart, F*ck yeah! Taco Bell, F*ck yeah! X2, F*ck yeah! Pentium D..............(Distant) fuck yeah?"

    wow this is the most F*cks I've seen in a single Anand post, or thread for that matter.

    F*ck it. I'm all for setting records :)
  • Da3dalus - Monday, May 9, 2005 - link

    When the time comes, an X2 shall be a nice upgrade from my current s754 3200+ :)
  • dougSF30 - Monday, May 9, 2005 - link

    What's with the opening bias?

    (1) AMD, unlike Intel and the 840EE, does not claim to have launched the X2. Providing a performance preview != paper launch.

    (2) AMD states in writing that the X2 will be available in June. Not "Q3 or Q4". This is the second time Anandtech has made these "late this year" comments which contradict AMD's official stated position, with no explanation.
  • Zebo - Monday, May 9, 2005 - link

    Thanks Anand:)

    DrMrLordX, if you really think it's poorly priced consider this. the lowest end San Deigo, aka the "value" line in that series, a 2.2 is $350. Adding another core is only 50% more money inside 4400.

    Don't even start looking at dual opteron 248's which cost $1000 just for processors, not to mention expensive ECC and mobos pluys it's slower.

    I see real value in the 4400 and I'm a huge proponet of $70 wonderchips like XP mobiles.

    This is a workstation chip with a cheaper than workstation price.
  • Ender17 - Monday, May 9, 2005 - link

    Great article BTW. AT is my fav review site.
  • Anand Lal Shimpi - Monday, May 9, 2005 - link

    Zebo

    2-2-2-5/1T

    Take care,
    Anand

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