Radeon R9 295X2 8 GB Review: Project Hydra Gets Liquid Cooling

Power Consumption: Introducing Our Equipment

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.

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MethodologyContact-free DC measurement at PCIe slot (using a riser card)Contact-free DC measurement at external auxiliary power supply cableVvoltage measurement at power supply
Test Equipment1 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 SupplyCorsair AX860i with modified outputs (taps)
Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
  • SVMreborn
    The pricing of this beast really impressed me.
  • Marsian Gustrianda
    Many people doubt about Dual GPU Hawaii will be Blow Up. It seems AMD really do well job. Nice Looking Card
  • ohim
    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)
  • ferooxidan
    Finally the review of this beast! Now continue reading
  • outlw6669
    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!
  • getochkn
    Surprised you didn't do a mining hashrate test on it to see what it can push out.
  • gunfighter zeck
    the name Dreadnaught originated from Dread Nothing or, fear nothing.
    Boss ship.
  • Maxamus456
    Hope this price stays low and not get bloated from bit con miners like its predecessors.
  • blubbey
    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.
  • marciocattini
    Wheres Tom's Hardware seal of approval? =( clearly this card diserves some love!