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Power Consumption: Introducing Our Equipment

Radeon R9 295X2 8 GB Review: Project Hydra Gets Liquid Cooling
By , Igor Wallossek

Three Generations Of AMD Dual-GPU Cards, Compared

Naturally, we're going to compare the power consumption of AMD's Radeon R9 295X2 to other CrossFire- and SLI-based setups. But first, we want to use our high-end equipment for a little experiment, comparing the company's newest dual-GPU card to its predecessors. The point is to figure out whether AMD is moving in the right direction with its flagship cards.

Meet Our Test Equipment

Our power consumption test setup was planned in cooperation with HAMEG (Rohde & Schwarz) to yield accurate measurements at small sampling intervals, and we've improved the gear continuously over the past few months.

AMD’s PowerTune and Nvidia’s GPU Boost technologies introduce significant changes to loading, requiring professional measurement and testing technology if you want accurate results. With this in mind, we're complementing our regular numbers with a series of benchmarks using an extraordinarily short range of 100 μs, with a 1 μs sampling rate.

We get this accuracy from a 500 MHz digital storage oscilloscope (HAMEG HMO 3054), while measuring currents and voltages with the convenience of a remote control.

The measurements are captured by three high-resolution current probes (HAMEG HZ050), not only through a riser card for the 3.3 and 12 V rails (which was custom-built to fit our needs, supports PCIe 3.0, and offers short signal paths), but also directly from specially-modified auxiliary power cables.

Voltages are measured from a power supply with a single +12 V rail. We're using a two-millisecond resolution for the standard readings, which is granular enough to reflect changes from PowerTune and GPU Boost. Because this yields so much raw data, though, we keep the range limited to two minutes per chart.

Methodology
Contact-free DC measurement at PCIe slot (using a riser card)
Contact-free DC measurement at external auxiliary power supply cable
Vvoltage measurement at power supply
Test Equipment
1 x HAMEG HMO 3054, 500 MHz digital multi-channel oscilloscope
3 x HAMEG HZO50 current probes (1 mA - 30 A, 100 kHz, DC)
4 x HAMEG HZ355 (10:1 probes, 500 MHz)
1 x HAMEG HMC 8012 digital multimeter with storage function
Power Supply
Corsair AX860i with modified outputs (taps)
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Top Comments
  • Editor's Pick
    18 Hide
    JoeArchitect , April 8, 2014 7:53 AM
    @marciocattini

    "Wheres Tom's Hardware seal of approval..."

    This is addressed in the conclusion of the article:

    "We have an estimated price and an estimated date for availability. The past several launches were peppered by misses on both fronts, and we’ve learned our lesson about recommending gear before you can buy it."

  • 17 Hide
    ekagori , April 8, 2014 8:16 AM
    I like what AMD has done, it's good to know they are making a better effort with high end parts. Hopefully all this goodness trickles down to the next generation 20nm consumer friendly products.
  • 17 Hide
    tristangl , April 8, 2014 7:48 AM
    ok that just prove that 4k gaming for the average joe is still not around the corner
Other Comments
  • 6 Hide
    SVMreborn , April 8, 2014 5:19 AM
    The pricing of this beast really impressed me.
  • 10 Hide
    Marsian Gustrianda , April 8, 2014 5:25 AM
    Many people doubt about Dual GPU Hawaii will be Blow Up. It seems AMD really do well job. Nice Looking Card
  • 9 Hide
    ohim , April 8, 2014 5:27 AM
    This card is like the Veyron of WV , show the world what you can do (R295x2) but you`ll still relay on the sales of your WV Golf for revenue (270x, 280x)
  • -2 Hide
    ferooxidan , April 8, 2014 5:40 AM
    Finally the review of this beast! Now continue reading
  • 13 Hide
    outlw6669 , April 8, 2014 5:47 AM
    Impressive performance, temperatures and fairly low noise!
    I would prefer a bit lower price, but this looks like a great card for the gamer that has everything!
  • 9 Hide
    getochkn , April 8, 2014 5:55 AM
    Surprised you didn't do a mining hashrate test on it to see what it can push out.
  • 0 Hide
    gunfighter zeck , April 8, 2014 6:01 AM
    the name Dreadnaught originated from Dread Nothing or, fear nothing.
    Boss ship.
  • 11 Hide
    Maxamus456 , April 8, 2014 6:14 AM
    Hope this price stays low and not get bloated from bit con miners like its predecessors.
  • 11 Hide
    blubbey , April 8, 2014 6:27 AM
    So let me get this straight. It runs pretty cool, quiet, performs well and (for the moment) is able to play a good selection of games at 4k admirably and is priced competitively. Plus if you are going to drop a bit more on watercooling your GPUs (which is a possibility if you're spending $1200+) that gives this card even greater value. Nice work AMD.
  • -2 Hide
    marciocattini , April 8, 2014 6:28 AM
    Wheres Tom's Hardware seal of approval? =( clearly this card diserves some love!
  • 7 Hide
    spp85 , April 8, 2014 6:31 AM
    Sheeeer muscle power
  • 0 Hide
    Plusthinking Iq , April 8, 2014 6:32 AM
    this is what i want for all my high end gaming, but i would rather like to see aio water cooling only and a 140mm version that could go silent if needed, full cover water block like the tundra series is some of the best. but single card is the best like a 780ti cooled with a 140mm aio at 500rpm and quiet pump. MAKE IT HAPPEN!
  • 0 Hide
    ferooxidan , April 8, 2014 6:54 AM
    After reading the article my conclusion is: we need a beefier GPU next year for a truly comfortable 4K gaming experience. OMG games this day really take tolls on our rig. Some games only hit around 40-ish and some even down to 30-ish fps on 4K. Imagine next year AAA titles, even this beast will be tamed.
  • 0 Hide
    Wisecracker , April 8, 2014 7:02 AM

    Vesuvius erupts !! ... nice job, Toms.

    Conspicuous by their absence are power, temp and noise numbers from the Green Team -- which likely means they got smoked (in a really good way) across the board by dual Hawaii.

  • 4 Hide
    AMD Radeon , April 8, 2014 7:34 AM
    good guy AMD
  • 17 Hide
    tristangl , April 8, 2014 7:48 AM
    ok that just prove that 4k gaming for the average joe is still not around the corner
  • 0 Hide
    chuckydb , April 8, 2014 7:50 AM
    I hope some OEM make the cooler with a double radiator. That card can be cooler and completely silent.
  • 18 Hide
    JoeArchitect , April 8, 2014 7:53 AM
    @marciocattini

    "Wheres Tom's Hardware seal of approval..."

    This is addressed in the conclusion of the article:

    "We have an estimated price and an estimated date for availability. The past several launches were peppered by misses on both fronts, and we’ve learned our lesson about recommending gear before you can buy it."

  • 2 Hide
    St0rm_KILL3r , April 8, 2014 8:04 AM
    Well, at 1440p r9 295x2 = gtx 780ti sli. But at 3840x2160 it totally dominates every gpu. Wondering if gtx 790 will be able to keep up with it.
  • 17 Hide
    ekagori , April 8, 2014 8:16 AM
    I like what AMD has done, it's good to know they are making a better effort with high end parts. Hopefully all this goodness trickles down to the next generation 20nm consumer friendly products.
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