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Efficiency and Performance per Watt

Efficiency: Core 2 Nukes Atom On The Desktop
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We calculated the average power requirements of the two systems during an entire SYSmark 2004 SE run. This reflects intensive use of the systems, using popular mainstream office and content creation applications. Surprisingly, the Core 2 Duo E7200 system required only slightly more power on average: 34 W vs. 30 W for the Atom 230.

We also tracked the total power both systems used to complete the SYSmark 2004 SE run measured in watt-hours. This metric gauges system performance per watt hour. Thanks to its faster performance, the Core 2 Duo E7200 system on the Foxconn G31 motherboard required 40 Wh to complete the entire benchmark, while the Atom machine, which is substantially slower, required 46 Wh and a much longer period of time (see diagram on the bottom of this page) to complete the workload. The Core 2 machine may require more power at peak loads, but less power for the specific workload. Expect the result to be more significant in favor of the Core 2 for processor-intensive workloads.

Finally, we calculated the SYSmark 2004 SE score per watt hour. The Atom 230 reached 2.2 SYSmark 2004 SE points per watt hour, while the Core 2 Duo machine did more than twice that: 5.65 points per watt hour. From an efficiency standpoint, the Core 2 Duo E7200 is vastly superior.

The diagram shows the system power consumption over the entire duration of the benchmark run, and it also shows how long the systems took to complete the workload. The Atom 230 took more than one hour and 30 minutes, while the Core 2 Duo system required one hour and 10 minutes. The Atom system usually didn’t exceed a 36 W maximum power requirement, but it continued to use power while the Core 2 system was finished. The power peaks of the Core 2 system were substantial, but they were exactly what you read: peaks. The 50+ W power consumption applies to only a fraction of the benchmark runtime.

Display all 67 comments.
  • 8 Hide
    slomo4sho , November 21, 2008 8:44 AM
    Thanks for the write up. I wish you actually compared the Atom to cheaper AMD CPUs like the 4850e instead of the core 2 though.
  • 0 Hide
    zodiacfml , November 21, 2008 9:02 AM
    quick follow up from the article on Efficient Motherboards which i mentioned that the power supply matters more than the motherboard for power efficiency.
    what's good in low power supplies is not really the efficiency, but they're lower in price and is usually less noisy. so indeed,you're right about to match the powersupply to the usual activity of the computer.

    the existence of an atom is not about power efficiency but lower die space then lower costs. as you see, the core2duo is almost 4 times the die space of the atom which reflects the three times performance advantage. also, i predict the atom will be more efficient at 0.8-1 GHz since the 1.6Ghz default speed is pretty high for this small chip.

    so, an atom system it is for NAS/server requirements. :) 
  • -1 Hide
    chouff , November 21, 2008 9:17 AM
    Slomo4shOThanks for the write up. I wish you actually compared the Atom to cheaper AMD CPUs like the 4850e instead of the core 2 though.


    They kind of did, here: http://www.tomshardware.com/reviews/shuttle-x27-atom,2038-5.html
  • 2 Hide
    blackwidow_rsa , November 21, 2008 9:23 AM
    The article states that the e7200 has a 800mhz fsb? shouldnt it be 1066mhz?
  • 3 Hide
    slomo4sho , November 21, 2008 9:27 AM
    chouffThey kind of did, here: http://www.tomshardware.com/review [...] 038-5.html


    Thats hardly a equal comparison... The AMD system was in no way build for power efficiency as it had a 4670 GPU.

    I want to see a fair representation of how well AMD holds up in the Power vs Performance discussion. Considering that you can get a MOBO + a 4850e for the price of a E7200, I would like to see how the two would compare when it comes to efficiency. Its also pretty unfair assessment of the atom vs a dual core processor, they really should have obtained a 330 for a more accurate assessment.

    Also, when will we be seeing a write-up on a variety of >400watt PSUs?
  • 4 Hide
    Mucke , November 21, 2008 10:35 AM
    Absolutely. If I want an efficient system I will take a 4850e + 780G-Board. It will still need more power but it will be usable in every day life without limitations.
  • 4 Hide
    Shadow703793 , November 21, 2008 11:19 AM
    What Intel needs to do is create a new chipset specifically for Atom. The Chipset uses up most of the power.
  • 1 Hide
    zenmaster , November 21, 2008 11:27 AM
    Intel's Chipsets overall need a examination from a power point of view.
    I think they are still on the 65nm process?
  • -1 Hide
    Pei-chen , November 21, 2008 11:39 AM
    Great article; I always knew nettop is a fad. It is too bad that sub 350w PSU is very difficult to find.
  • 4 Hide
    nihility , November 21, 2008 11:50 AM
    I don't understand why you didn't underclock/undervolt the C2D processor (and atom too). That would have been very meaningful data.
  • 1 Hide
    kureshii , November 21, 2008 12:24 PM
    The results are not all that surprising; in terms of power efficiency, the Atom setup is already "crippled" by the 945GC. It would be nice to do a rerun once Poulsbo mini-ITX motherboards are out. There are already some available, but they are not quite mainstream yet.

    I'm pretty sure the Core 2 will still beat out Atom+Poulsbo for more processor-intensive applications, but I'd like to see how the significantly lower idle power for Poulsbo will affect things.
  • 1 Hide
    pullmyfoot , November 21, 2008 1:29 PM
    An ok writeup. Pretty interesting. However it seems like the article was just thrown together without much thought of the content - the scope is so extremely limited. 2 CPUs? common.. You can do better than that. This seems to be the case with most of their recent articles and it seems like these articles are just there for the sake of being there.

    What happened to AMD CPUs? And it would be interesting to see how the E7200 performed undervolted and underclocked. Seeing how close its idle power is to the Atom, it might even take up less power.
  • 1 Hide
    enewmen , November 21, 2008 1:48 PM
    Just wondering.
    I have a 4 year old Pentium M @ 1400 Mhz.
    Seems plenty fast enough - can even play Oblivion on low settings. This makes me wonder if the Atom is fully capable of everyting except for media recoding, high-end games, etc.
    The Pentium M would have been a better comparison since everyone knows the C2D is whole lot faster, etc. blah blah
  • -1 Hide
    zcubed , November 21, 2008 2:33 PM
    great article. i wonder what the e7200 would perform like in a mini-itx board power-wise. there are 6 available(3 different types of chipsets) on newegg that will support it. that would probably also be a more even comparison with the atom.
  • 0 Hide
    Anonymous , November 21, 2008 2:39 PM
    Hi,

    i really wish for this kind of comparison, you include the intel Pentium-M & Pentium-III M for comparison.

    I have an intel Pentium-M, and I wish I know if I upgrade to intel atom would it be faster or slower.
  • 0 Hide
    JimmiG , November 21, 2008 2:49 PM
    Pretty interesting, but the point of the Atom isn't to give the most performance per watt. It's about providing "good enough" performance for stuff like browsing the Internet, at the targeted power draw. If you plan on doing rendering, gaming, converting video etc., a low-end Core 2 is a better choice. Also current Atom chipsets draw much more than the CPU itself which kind of defeats the purpose of the Atom on the desktop (mini-ITX). This will improve once Atom gets its own memory controller, possibly integrated GPU core, and Intel comes out with more efficient chipsets. Finally the cheapest Atom CPU costs $29, quite a bit cheaper than any Core 2 CPU.
  • 0 Hide
    nmathew , November 21, 2008 2:54 PM
    nihilityI don't understand why you didn't underclock/undervolt the C2D processor (and atom too). That would have been very meaningful data.


    I fully agree. In my experience, C2D processors easily undervolt a fair bit. Set the C2D to a 800MHz bus, and look out. I wonder how close the e7200 or the lower L2 cache E5200 underclocked and undervolted could get to passive cooling. Furthermore, while I understand the desire for an apples to apples comparison, testing the e7200 with a lower power modern chipset would have been nice. There is no real need to hamper it with an older inefficient platform if the goal is to show that a C2D system can be more efficient in low wattage situations than an Atom based one.
  • 0 Hide
    Christos , November 21, 2008 3:16 PM
    The point of Atom isn't just low power requirements. It's about small die size in order to be used for netbooks. Try to fit a celeron in one...

    I believe the desktop versions of Atom aren't really useful. As this article proves using a low end ordinary desktop cpu can do more for the same power draw.

    Since i have a quite powerful desktop pc, but i need some portability too, i chose an Acer Aspire One. I really love it! It can do much more than browsing the net. I use it for developing in Visual Studio 2008, i use Office 2007, i even play games like Star Wars KOTOR with it. Atom may not be similar in performance to Core 2, but it is perfect for netbooks and provides more than enough power for the average user.

    But frankly there is no point in bying an Atom for a desktop pc.
  • 0 Hide
    Area51 , November 21, 2008 3:21 PM
    Shadow703793What Intel needs to do is create a new chipset specifically for Atom. The Chipset uses up most of the power.

    I think they are including an IMC on the next version.. That should reduce power consumption to the platform significantly.
  • -2 Hide
    tsponholz , November 21, 2008 3:26 PM
    Love the comparison...

    I have some follow up questions that the board may be able to answer:
    1) Since system power maxed at
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