AMD Radeon RX Vega review: Vega 56, Vega 64, and liquid-cooled Vega 64 tested

Find out whether RX Vega was worth the wait.

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Power, heat, noise, clock speeds


We test power under load by plugging the entire system into a Watts Up meter, running the intensive Division benchmark at 4K resolution, and noting the peak power draw. Idle power is measured after sitting on the Windows desktop for three minutes with no extra programs or processes running.

power draw Brad Chacos/IDG

Holy hell, Vega 64 uses a lot of juice. And that’s not even in Turbo mode.

AMD spent a lot of time talking up Vega’s power efficiency, but it’s clear the company really cranked on the clock speeds to bring performance in line with the GTX 1080, especially when you consider the power savings that HBM offers over traditional memory. At 347 watts of total system power draw, the air-cooled Vega 64 uses 106W more power than the GTX 1080 Founders Edition—heck, even the mightily overclocked EVGA GTX 1080 FTW only used 248W. The liquid-cooled model draws an astonishing 402W. That’s roughly 100W more than even our overclocked GTX 1080 Ti XLR8 requires.

A silver lining for AMD? Vega’s sky-high thirst for power makes the 60W gap between the GTX 1070 and Vega 56 look far less imposing.

While we didn’t measure it here, Radeon Chill can indeed bring down your power use and temperatures significantly—but only in the whitelisted games, and you have to enable it manually (which you should do)! Frame Rate Target Control can also help reduce GPU load. Seeing these Vega power results, it becomes more clear why AMD invested so much in power-saving software features in recent months.

Heat and noise

We test heat during the same intensive Division benchmark at a strenuous 4K resolution, by running SpeedFan in the background and noting the maximum GPU temperature once the run is over.

gpu temp Brad Chacos/IDG

Despite using so much more power than the GTX 1070 Founders Edition, the Vega 56 actually runs much cooler, topping out at 66 degrees Celsius. The air-cooled Vega 56 hits the same 82-degree Celsius max as the GTX 1080 and 1080 Ti Founders Edition cards. AMD’s blower-style reference cooler gets awfully loud under load though, vapor chamber or no.

Speaking of loud, our liquid-cooled Vega 64 suffered from a buzzing coil whine when sitting on menus or the Windows desktop. It goes away in-game, but it isn’t very pleasant. The card hovers between 55 degrees Celsius and its max of 60 degrees Celsius during testing. That’s slightly warmer you’d expect from a liquid-cooled card; the older Fury X never topped 56 degrees Celsius in our benchmarks. It’s also worth noting how that 60-degree-Celsius maximum for the liquid-cooled version isn’t much chillier than the PNY GTX 1080 Ti XLR8’s triple-fan solution, and that GeForce card delivers a whole lot more performance for roughly the same price.

Given Vega's wild power draw, the liquid-cooled model probably would've been more effective with a 240mm radiator rather than the included 120mm version. 

Clock speeds

All of these cards hold their rated boost speeds pretty consistently, with some slight, temporary bumps up or down in performance. Here are screenshots of Radeon Wattman graphs of each card’s performance during Deus Ex: Mankind Divided benchmark runs. You can click on them to enlarge each, with the orange line indicating clock speeds.

The Vega 56 varies between 1,474MHz and 1,312MHz steps.

56 deus ex dip Brad Chacos/IDG

The Vega 64 usually sticks to its 1,536MHz boost speed.

64 deus ex Brad Chacos/IDG

The liquid-cooled Vega 64 is mostly rock solid at 1,668MHz, but it sometimes dips to 1,560MHz and spikes as high as 1,750MHz.

64 lc deus ex Brad Chacos/IDG

Next page: The FreeSync variable

At a Glance
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