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Updated: AMD 785G: The Venerable 780G, Evolved

Power Usage Benchmark

AMD has claimed great power savings with the 785G chipset and its Powerplay feature. Let's see how the platforms compare:

Now this test isn't an ideal way to compare the 785G to the 780G, as we only have a 790GX board on hand and underclocked it to simulate the 780G specifications for this test. However, the power draw difference is so slight between the 785G and simulated 780G that we doubt there'd be much of a difference with an actual 780G board.

Comparing platforms, it looks like the E7200 CPU on the Intel LGA 775-based boards uses less power than the Phenom II X2 550, which is no surprise, as the Phenom II X2 is a much faster CPU with a lot more cache. The Athlon II X2 250, however, sips even less load power than the Core 2 Duo E7200.

Analysis

Now, I'm all for environmental friendliness, but all too often I think the bottom line cost for an end-user is overlooked. So let's examine the power savings of the E7200 over the Phenom II X2 550.

At idle, the Phenom II X2 is drawing the highest load: 92 W on the 790GX motherboard. In contrast, the E7200 is drawing 66 W on the most efficient platform, Intel's G45. It looks big on the chart, but it's a difference of 26 W.

In the most populated coastal cities of the United States, electricity costs are the highest in the country at about 15 cents per kilowatt/hour. With this information, we can calculate the cost to use the Phenom II X2 550 compared to the Core 2 Duo E7200.

Let's compare the worst-case scenario, a PC with a Phenom II X2 550 and a 790GX motherboard, to the best-case scenario, a machine with a Core 2 Duo E7200 paired with a G45 motherboard. If you left a Phenom II X2 550/790GX-equipped PC in active idle state for 24 hours a day, you would be billed $34.16 more compared to the E7200/G45 in electricity costs every calendar year, and that's assuming you leave your computer on in an active state and don't turn it off or let it enter sleep mode.

This equates to big numbers for massive corporations deploying thousands of PCs, but for the home user it shouldn't be as much of a concern. In a home environment, I'd recommend the faster processor so that the performance is there when you need it. As for environmental concerns, Mother Earth is far better served by simply turning your PC off when it isn't being used.

There are two lessons to be learned here: first, if you really care about the environment, turn your PC off (or at least configure it to enter sleep mode) when you're not using it, and second, don't be afraid of purchasing a better processor for fear that it will cost you big money in power consumption.

  • macer1
    the real question is how would this perform if mated to an Atom processor in an nettop.
    Reply
  • mcnuggetofdeath
    "refined architecture" ? To my knowledge, and please correct me if im wrong, all that was changed between the original phenom and the phenom 2 was the addition of more L3 cache allowing it to do more simultaneously and a die shrink allowing for higher clocks. That does not a refined architecture make. When AMD added an on die memory controller to their processors years ago they had made a huge advancement in architecture. Im sad to see them fall away from the performance crown. Here's hoping their new Bull Dozer architecture brings something genuinely intriguing to the table.
    Reply
  • mcnuggetofdeath
    ^^^ and support for DDR3. Although thats a change to the board, not the CPU.
    Reply
  • anamaniac
    Very interesting.
    A integrated GPU that can game. =D

    Makes my lil Pentium D with a 4670 seem puny...
    3.3GB/s memory bandwidth (single channel DDR2 533... though 2 sticks, it runs in single channel... damn prebuilts) also seems sad on my rig...

    macer1the real question is how would this perform if mated to an Atom processor in an nettop.
    Good question. A dual core Atom with a 4200 integrated would be nice.
    We all know Intel makes shitty mothebroards and AMD makes kickass motherboards anyways.
    Reply
  • SpadeM
    mcnuggetofdeath^^^ and support for DDR3. Although thats a change to the board, not the CPU.
    Not correct, the P2 has a built in memory controller so the switch to ddr3 affected that controller
    Reply
  • apache_lives
    anamaniacVery interesting.A integrated GPU that can game. =DMakes my lil Pentium D with a 4670 seem puny...3.3GB/s memory bandwidth (single channel DDR2 533... though 2 sticks, it runs in single channel... damn prebuilts) also seems sad on my rig...Good question. A dual core Atom with a 4200 integrated would be nice.We all know Intel makes shitty mothebroards and AMD makes kickass motherboards anyways.

    Native ram for a pentium d is PC4200 which has a max of 4.2gb/s per channel etc and the FSB has the max of 6.4gb/s

    The Intel atom would most likely underpower any video card out there, and Intel does actually make a good reliable business platform where video performance is not required etc
    Reply
  • I'm sorry, is this an Intel benchmark site? All other reviews put SYSTEM power consumption for Athlon II 250 well below Intel E7200.
    Reply
  • aproldcuk
    This article raised a lot of questions for me. What about Hybrid Crossfire for example? What kind of cards can be used together with this new IGP? Is the discrete graphics card on standby if no performance is required? If no then how much extra outlet wattage is expected? And how much extra if actively in use? I'm interested in using the 785G solution in the 24/7 HTPC setup with the possibility to do occasional gaming as well. My current setup with 690G chipset and Athlon 64 X2 BE-2350 CPU draws around 50 watts most of the time and up to 90 watts under heavy load. Is it too much to expect similar levels from 785G and Phenom II X3 705e combo for example?
    Reply
  • wh3resmycar
    when can we see the mobile version of this? this is most certainly a welcome update compared to the 780g-hd3200 chipset. and beats any nvidia igp hands down. id love to see this on an $700-$800 laptop. good thing im still holding back on buying a new notebook.
    Reply
  • Pei-chen
    Good timimg, I was wondering if 785G is better than 790GX or not yesterday. Thanks.
    Reply