Power Consumption

As always, we measured power consumption of the entire system at the wall outlet. First up is power consumption with the test system at idle. Here AMD's Cool 'n Quiet and Intel's EIST really come into play and do their best to reduce power consumption:

System Power Consumption while Idle

As you can expect, based on the old 90nm Smithfield core, the Pentium D 805 isn't exactly the coolest running chip on the block. In fact, the Athlon 64 3000+ consumes less power under full load than the Pentium D 805 does with both of its cores idling. Note that the higher power consumption on the two Opteron parts is because Cool 'n Quiet would not work with the Opterons on our test platform.

System Power Consumption under Load

The picture doesn't get any prettier under full load. If you're expecting the Pentium D 805 to be a cool running, quiet chip, you're going to be sorely disappointed. If power consumption matters to you then you're far better off with a Pentium D 900 series or an Athlon 64 X2.

Looking at the long-term prospects, power costs money, so how long will it be before the lower power X2 3800+ reaches the break-even point? If we go with a typical $.10 per kWHr, the X2 3800+ consumes 37W less at idle and 48W less at full load. If that seems like a lot of power initially, it actually only works out to $32-$42 per year, running both systems 24/7. That means you're looking at a minimum of four years to reach equivalence in price+power. What about the 920 versus 805 power costs? The difference there is even less in terms of power use, so even at full load you're looking at $16 per year, or seven years to reach the break-even point.

Of course, you can't just look at power in most instances. The X2 3800+ will offer you faster performance during its lifetime, so it definitely warrants consideration. Lower power, lower heat, lower noise, and higher performance are all nice things to have.

Note: Pentium D 820 numbers were excluded from the power comparison due to technical difficulties with our test platform at the last minute. Based on the data here, you can expect it to consume more power than the Pentium D 805.

Gaming Performance using F.E.A.R. and Quake 4 Final Words
Comments Locked

51 Comments

View All Comments

  • poohbear - Friday, April 7, 2006 - link

    amazing how a dualcore opteron @ the same speeds as a non dual core can have a 30fps increase in quake4! :0 (aside from the extra 1mb cache) hope that's a sign of things to come.
  • Sunrise089 - Friday, April 7, 2006 - link

    Coming after the Black and White article, it's easy to see the high and low in AT writing. This artcle was fantastic, especially page 2, where Anand comments on all the possible chips in the low-middle marketplace. It's nice to see my Opteron 144 still able to win a benchmark. How important this info will be with Conroe around the corner is anyone's guess, but it's nice to see all the information put out there so effectively.

    Now if you will, write up an overclocking story on the Opteron 144, X2 3800+, Pentium D 805, and Pentium 4 3.2ghz.
  • Calin - Friday, April 7, 2006 - link

    And power use for the overclocked 805 is a must :D
    there goes the idea of having a small, silent, somewhat high performance computer with an 805 :(...
  • Pete84 - Friday, April 7, 2006 - link

    Why wasn't the chip overclocked? They supposedly have very good headroom.
  • JarredWalton - Friday, April 7, 2006 - link

    Read the last page. That article is in the works.
  • Viditor - Friday, April 7, 2006 - link

    As this is the low end, could you guys throw in an overclocked Sempron as well?
    Just askin...:)
  • stephenbrooks - Saturday, April 8, 2006 - link

    Agree on the Sempron. Also wondering about the new Celeron 355 at 3.33GHz as the poor 351 gets left behind in all those graphs (though it is cheaper - I almost want the $ figure written on the graphs so I can tell if it's a fair competition or not).

    I wonder why Intel is making no 512KB L2 cache chips?
  • Questar - Friday, April 7, 2006 - link

    Why?

    This thing would mop the floor with a Sempron.
  • Viditor - Friday, April 7, 2006 - link

    quote:

    This thing would mop the floor with a Sempron.

    Never let the facts get in the way of a good story, eh? :)

    Seriously guys, since Semprons are in this same and slightly lower price range, it would be of great benefit to see a comparison so that we can make some buying decisions.

    Cheers!
  • mino - Friday, April 7, 2006 - link

    Actually Sempron 3100+ has about the same performance as A64 3000+.

    even 2800+ would be faster than 805 in singlethread scenario.

    Not saying 805 is bad (actually it is now the best value for money).

    Jus your comment is OFF.

Log in

Don't have an account? Sign up now