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Power Draw: Test System And Methods

MSI R9 290X Lightning Review: The Right Way To Cool Hawaii
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Test System and Power Draw Measurement

We partnered up with HAMEG Instruments (Rohde & Schwarz) to implement a state-of-the-art test system for precise, short interval power and performance measurements.

Only modern lab instruments can keep up with the challenges that AMD’s Power Tune and Nvidia’s GPU Boost present (namely, huge swings in dynamic power consumption). We feed all relevant currents and voltages into a multi-channel 500 MHz oscilloscope (HAMEG HMO 3054), which can be remote-controlled and is able to retain the test data.

We measure the currents with three calibrated DC current clamp probes (HAMEG HZO50). Two of them, 3.3 and 12 V, take their readings at a custom-made riser card, which can reliably pass PCIe 3.0 signals, and one of them at a specially-modified PCIe power cable. All voltages are measured at the single-rail power supply, which we slightly modified to allow better access.

Our time resolution is now a mere 2 ms, which can measure and log all load transients incurred by AMD’s Power Tune and Nvidia’s GPU Boost. In order to keep the volume of data manageable, we limit the duration of a test run to two minutes.

Test Method
No contact current measurement at the PCIe slot (Riser card)
No contact current measurement at the external PCIe power cable
Voltage measurement at the PSU
Test Equipment
1 x HAMEG HMO 3054, 500 MHz four-channel oscilloscope
3 x HAMEG HZO50 current probe (1 mA - 30 A, 100 kHz, DC)
4 x HAMEG HZ355 (10:1 probe, 500 MHz)
1 x HAMEG HMC 8012 DSO
Test Bench
Microcool Banchetto 101
Power Supply
Corsair AX860i with slightly modified connectors

What Happens Within 100 ms?

A lot! We log the power draw with three probes at a 2 ms interval and pick a representative 100 ms window. Then we plot the resulting 50 data points in a graph.

Looking at the graph, you almost have to feel sorry for the power supply. Power draw through the PCIe power cables jumps from 140 to 352 W within a few milliseconds. You can't expect just any old generic PSU to cope with that. The two test points at the PCIe riser cards do not exhibit such drastic load changes.

We like that neither AMD nor Nvidia max out the PCIe slot connector's output rating, which is 75 W. Those auxiliary power cables bear the brunt of the load. Nor are there drastic load transients on the motherboard connector. All of this helps ensure system stability, benefiting multi-GPU setups in particular.

Now let's take a look at power consumption in real-world workloads.

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Top Comments
  • 10 Hide
    solix , April 15, 2014 11:10 PM
    Unless I am mistaken you burn 3 slots with this guy. For how close this is to the Tri-x in thermals and acoustics, but with the loss of a slot and the added price, meh. Tri-x still seems like the best value proposition.
Other Comments
  • -5 Hide
    blackmagnum , April 15, 2014 11:07 PM
    If it costs 750 bucks, it should come with water-cooling. Why the need to slap on a pound of metal to cool it if there was a more customer friendly way?
  • 10 Hide
    solix , April 15, 2014 11:10 PM
    Unless I am mistaken you burn 3 slots with this guy. For how close this is to the Tri-x in thermals and acoustics, but with the loss of a slot and the added price, meh. Tri-x still seems like the best value proposition.
  • -2 Hide
    CaptainTom , April 16, 2014 12:09 AM
    I just want to point out how silly the 780 Ti is priced. People, this card trades blows with the 780 Ti while giving you an extra GB of VRAM. It should cost at least as much as the 780 Ti. Or better yet, the other way around! ;) 
  • 7 Hide
    AndrewJacksonZA , April 16, 2014 12:43 AM
    Quote:
    Unfortunately, in order to increase this card's GPU voltage, you have to register with MSI for a special license. This isn't given out freely; only professional overclockers can get their hands on it.

    Whoa, wait, what???
  • 5 Hide
    dscudella , April 16, 2014 1:13 AM
    As of my post, the pricing on Newegg for the mentioned cards:

    MSI 290x Lightning $699.99 + $4.99 shipping
    Sapphire 290x Tri-X OC $649.99
    Sapphire 290x Tri-X $639.99
    Gigabyte 290x Windforce $579.99 ($549.99 after rebate)

    This makes the Lightning $125 ($155 after rebate) more expensive than the Windforce. MSI is really stretching the price here.
  • 2 Hide
    zzzaac , April 16, 2014 1:21 AM
    $899 or 841 USD where i'm from for this card. Got to admit though, 3 slot cards are really unappealing for me.

    Got to agree that the Tri-X seems a better value proposition
  • -3 Hide
    cats_Paw , April 16, 2014 2:04 AM
    A bit useless review:
    The main aspect of a GPU and its most important job is to make games run smooth.
    In this review there is only a Performance ratio chart. This does not give the important data at all.

    I dont care if that GPU has 80 or 85 FPS in farcry3, but I Do care if it has 25 or 30 on more demanding games/settings.
    Finally, this card seems like itsmissing its purpouse a bit.
    It has a huge heatsink, but dosent actually run cool or quiet.
    It has an OC that is decent but dosent increase performance that much.
    You could water cool that GPU for a similar price and get better performance in every aspect as long as you are willing to have a loop in your PC.



  • 1 Hide
    redgarl , April 16, 2014 2:59 AM
    Where is your review of the Powercolor PCS+ R290x...? From all the review I have seen, not only they are cheaper, but perform better I from what I am seeing, smaller.
  • 2 Hide
    ubercake , April 16, 2014 3:49 AM
    That "Certificate of Quality and Stability" is humorous...

    "I hereby declare this video card to be of the utmost quality and thereby further and henceforth declare this same electronic device to be 101% stable to the fullest of my capabilities to determine it as such. Sincerely, Your Mom".

    Definitely something to frame and hang on your wall above the monitor.
  • 5 Hide
    ewok93 , April 16, 2014 4:47 AM
    I feel like it would be much more cost effective to go with water cooling, it would definitely be much lighter. I may be wrong, though, as that heatsink is pretty freaking massive. It just seems like past a certain point, air cooling can only do so much, and can only take up so much space.

    If you're just going for overkill, I want to see one of these with phase change cooling. It can't cost that much more, can it?
  • 4 Hide
    admin$ , April 16, 2014 5:24 AM
    I used to be a huge fan of AMD and was excited for the 290x because of its performance for the price. But this card is slower and more expensive than the 780ti. I can't justify purchasing a slower card for more money just because I am loyal to the AMD brand. Sorry AMD, I just bought my asus direct cu ii gtx 780ti for 709$ at frys (they matched amazon). It was the right choice too. Probably the next to go will be OC'd 8350. :(  Its just not the XP 3200+ days anymore.
  • 0 Hide
    rwinches , April 16, 2014 5:48 AM
    As I read this Amazon showing $650

    Anyway 3 slots? No. But it looks good on you though.
  • 2 Hide
    Haravikk , April 16, 2014 6:35 AM
    Personally I think that if you're getting into three-slot 1.5kg territory to air-cool a graphics card that you may as well switch to liquid cooling, especially for the price. I mean, for the extra cost of this limited edition you could get a cheaper R9 290X compatible with the Kraken G10 adaptor, and use that with any suitable all-in-one cooler. For around the same cost it should give you better, quieter cooling and a lot less stress on your poor motherboard.
  • 0 Hide
    forged , April 16, 2014 7:02 AM
    that power drop might be similar to the unusual voltage drop that i observed with 780 Lightning. I didn't notice the effect on gaming though. It's just something not common to the other cards i have owned.
  • 1 Hide
    heero yuy , April 16, 2014 7:23 AM
    so this thing is supposed to be good for overclocking and it has a huge possible power draw to facilitate that
    yet apparently in order to increase the voltage you need to be a professional overclocker in the eyes of MSI

    am I missing something here?
  • 0 Hide
    unknown9122 , April 16, 2014 7:25 AM
    What a monster.
  • 1 Hide
    geok1ng , April 16, 2014 7:36 AM
    there is no reason to ditch VGA completely. A single DVI-I output would improve the compatibility of the card without changing the out layout too much. 2 DVI-D are a compromise, if not downright stupid.
  • 2 Hide
    ykki , April 16, 2014 8:18 AM
    MSI needs to rethinking its marketing strategy
  • 0 Hide
    Steveymoo , April 16, 2014 9:01 AM
    So ridiculously huge. And so expensive!!

    Damnit.
  • 0 Hide
    Achoo22 , April 16, 2014 9:38 AM
    Why are there no 780 and 780TI boards in the sound and heat comparison charts?
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