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Power, Performance, and Efficiency

NForce 780a Hybrid SLI Tested

The big thing that separates the nForce 780a SLI from lower-cost GeForce 8000-series chipsets is its nForce 200 PCI-Express 2.0 bridge, which adds support for two high-end cards at full bandwidth to what might otherwise have been a mundane product. This feature lends itself to the ultimate in gaming system efficiency by shutting off the unneeded cards when the user exits a game, but our motherboard died before we could test this feature on a 9800GX2.

Everyone knows the 9800GX2 is a "power hog" that really deserves such energy-saving technology, but any discussion of efficiency must also consider the amount of work being done by that energy.

We might not have any HybridPower data, but we can at least consider the performance gained by the lesser cards in GeForce Boost mode before making any judgments about the 9800GX2’s basic efficiency.

The low-cost 8400GS and 8500GT got their greatest GeForce Boost in Supreme Commander, but both cards lost some performance in Prey with this technology enabled.

No performance gains are free, and the onboard graphics processor certainly requires some power to function. We tested each configuration in both 2D and 3D mode, using the HD Rendering 1 benchmark (Canyon Frow_even) from 3D Mark 2006 to find the maximum requirement. The following chart shows "global" power consumption for the entire system.

The onboard graphics controller added only a few watts to each low-end configuration, while the 9800GX2’s extreme power consumption leaves us devastated over the loss of our test motherboard prior to HybridPower evaluation.

It’s still important to remember that efficiency is a ratio of work output to energy input, and the 9800GX2 is an impressively powerful card. At the other end of the market, the 780a’s onboard graphics processor’s scant performance is compensated by its miniscule power consumption. Our motherboard failure may have prevented us from answering any questions today about HybridPower on the 9800GX2, but is the other side of Hybrid SLI - known as GeForce Boost - also a boon to efficiency?

It may seem hard to believe, but the 9800GX2 is actually the most efficient card in our evaluation, thanks to its enormous performance advantage over low-cost cards. GeForce Boost also does well, providing a performance boost that surpasses its power consumption.


Today we considered the GeForce Boost capabilities of NVidia’s newest performance chipset, but it’s really a shame our test board didn’t live long enough to provide any answers about the efficiency of HybridPower. Next week we’ll see how the 780a SLI stacks up against AMD’s 790FX in general performance.

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  • 0 Hide
    cappster , May 6, 2008 2:36 PM
    I am interested in seeing a high end card paired with the hybrid graphics. It kind of leaves an empty taste in my mouth with just testing the low end crap cards.
  • -1 Hide
    scooterlibby , May 6, 2008 2:42 PM
    "we were unable to test the chipset’s HybridPower capabilities"

    You'd think after writing this sentence they'd realize the article is pretty much moot, just read the title.
  • 0 Hide
    scooterlibby , May 6, 2008 2:43 PM
    aggh nevermind I'm the idiot! I love you Tom's!! Take me back.
  • -1 Hide
    Anonymous , May 6, 2008 4:30 PM
    Why publish an incomplete article? Who wants an 8500 on a new board?
  • 4 Hide
    piratepast40 , May 6, 2008 5:02 PM
    Why is there no mention of the 780g platform and Hybrid Crossfire? The author makes it sound like Nvidia is the first out the door with the concept. I'm not saying one is better than the other but the bias is rather striking.
  • 0 Hide
    Crashman , May 6, 2008 7:36 PM
    The article had to be published on release day, in spite of the motherboard failing before 9800GX2 testing could be completed. NVidia isn't going to be happy either, considering the target market of the chipset.
  • 0 Hide
    johnbilicki , May 6, 2008 8:28 PM
    Asus is the Realtek of motherboards.

    You guys should RMA the board when it becomes publicly available provided it's not some supped up board merely for review purposes as Asus has been busted for. Oh whoever does the RMA should do it from home so they don't make the review connection so you can get the same crappy treatment I did.

    Then when you receive the RMA replacement please let us know if it's new or used and if there is any sperm on the north bridge.

    If the review wasn't marred by an Asus product then this would have been a top read. Well, at least we know nVidia has something fresh for AMD. We'll just have to wait until the Asus flood dries up so we can get reviews from manufacturers with class such as Gigabyte and MSI. Right now there is only decent true 16X+16X SLI motherboard for socket AM2 on Newegg, it's a Biostar motherboard.
  • 1 Hide
    wild9 , May 6, 2008 8:40 PM
    Many games are limited by the CPU rather than the graphics chip, so we needed a top processor model.

    Past a certain resolution, I think most games are limited by the GPU. Some games will show hardly any difference between a fast processor and a slow one, assuming both processors are modern dual-core parts. The differences between Intel and AMD processors can be large, but it's not consistent.
  • 0 Hide
    wild9 , May 6, 2008 8:42 PM
    So now we have nVidia 780a and AMD 780g chipsets..both available for AMD-based motherboards. This might lead to some confusion amongst prospective consumers.
  • 0 Hide
    wild9 , May 6, 2008 8:52 PM
    At the other end of the performance scale, the 9800GX2 is so powerful that the AMD Phenom X3 8750 is unable to keep up (Prey).

    lol, 112fps..that's more than enough - if you have a spare Phenom you don't need I can put it to good use :D 
  • 0 Hide
    royalcrown , May 7, 2008 6:18 AM
    even at a 300 percent boost, the hybrid would be CRAP...ooooh all the way from 2 to FOUR whole fps...wheee...lemme jump up n down !
  • 1 Hide
    chaos23 , May 7, 2008 8:01 AM
    I think Hybrid SLI wasn't made to be paired with high end graphic cards like the 9800GX2. That card shouldn't have been included in the test.
  • 0 Hide
    Christopher1 , May 7, 2008 9:43 AM
    This would be a good way to cut down on power consumption. When the graphics card isn't under stress, it could use the integrated graphics chipset. When it was under stress, it could automatically switch to the discrete graphics card/s or use both the integrated and discrete in tandem.
  • -1 Hide
    caskachan , May 7, 2008 10:27 AM
    isnt at least 1/3 of people expecting high end card+integrated performance gain, to see if it matters int he descicio when buying for a mobo for their super ultra high end vid card?
  • 0 Hide
    derek85 , May 7, 2008 12:56 PM
    What about AMD's 780G chipset? Shouldn't there be a comparison between the two at least??
  • 0 Hide
    emergancy exit , May 11, 2008 1:07 AM
    yeah ATI is already doing this has been for half of a year ......

    i guess it's just a small boost in horesepower a berley noticeable one if that but evry little bit helps
  • 0 Hide
    stridervm , May 11, 2008 2:46 PM
    I wish there was a comparison between Hybrid Crossfire and Hybrid SLI, even if it will be a little unfair (Due to Intel's processors being more powerful.) but at least it will get us a rough idea.)
  • 0 Hide
    Anonymous , October 17, 2008 9:51 PM
    When will we see a GeForce 9400 mGPU paired up with a 260 or 280? I wanna see how that preforms! (it's going to be my next motherboard, I think)