Sapphire Nitro+ Radeon RX 64 Limited Edition review: Taming Vega's flaws with brute force

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At a Glance
  • Sapphire Nitro+ Radeon RX 64 Limited Edition

Four long months after AMD’s flawed Radeon Vega graphics cards launched, custom versions are finally starting to trickle out—and the wait was worth it. The monstrous, yet luxurious Sapphire Nitro+ Radeon RX 64 Limited Edition relies on brute force to squash the most troubling problems that plague reference Vega cards. This beast sports the most wildly effective cooler to ever cross our test bench, and it manages to toss in a factory overclock while providing impressive tools for enthusiasts to push performance even further.

Curing Vega 64’s terrible heat and noise requires tradeoffs, though. Keeping the Sapphire Nitro+ Radeon RX 64 Limited Edition cool and quiet requires an awful lot of metal—and an awful lot of power. Then there’s the cost: At $659, this card is priced closer to a GeForce GTX 1080 Ti than Vega’s traditional rival, the GTX 1080. Is it worth the premium?

Let’s dig in.

sapphire radeon vega 64 nitro le 1 Brad Chacos/IDG

Sapphire Nitro+ Radeon RX 64 Limited Edition specs and features

Like most custom graphics cards, the Sapphire Nitro+ Radeon RX 64 Limited Edition puts its own unique spin on things, but shares many of the same tech specs as the reference GPU. Here’s a look at the core Radeon Vega tech specs before we examine Sapphire’s own tweaks.

radeon rx vega 64 specs AMD

Usually we kick off a graphics card review with a discussion about the tech specs but that’s not what’s most noteworthy about this card—instead, it’s the sheer size of the custom cooling solution. It’s hard to tell in these pictures but the Sapphire Nitro+ Radeon RX 64 Limited Edition is an absolute monster of a graphics card, dwarfing traditional two-slot designs in every dimension. This beast goes three slots deep, 4.75-inches wide, and 12.25-inches long. It’s big. By comparison, AMD’s Radeon RX 64 reference card sports a two-slot design that’s 3.75-inches wide and 10.5-inches long.

The Nitro+ Limited Edition is so massive, in fact, that Sapphire ships it with a nicely constructed GPU support bracket to keep the card from sagging in your case. The black nickel-plated bracket doesn’t demand any precious additional PCIe slots, unlike some aftermarket GPU supports, and it complements the look of Sapphire’s Nitro branding. The company plans to sell it separately as well.

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The Sapphire Nitro+ Radeon RX 64 Limited Edition is so big, it comes with a support bracket.

Sapphire tells me the Nitro+ Limited Edition was designed to let overclockers push Vega 64 as far as possible, and the card’s construction is proof of that. The Nitro+ Radeon RX 64 Limited Edition returns to a vapor-chamber cooling solution similar to Sapphire’s well-received Vapor-X models during the Radeon R9 200-series era.

That’s bolstered by six nickel-plated heat pipes (three 3mm, three 6mm) that help to keep the GPU and high-bandwidth memory stacks chilly, topped by an impressively gargantuan heat sink. The VRMs on this 14-phase card get a separate chamber of their own with two dedicated 6mm heat pipes and use black-diamond chokes, which Sapphire claims are 10 percent cooler and 25 percent more power efficient than standard chokes.

Like I said: Lots of metal.

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Not one, not two, but three large fans sit atop the heatsink. They won’t kick into action until the GPU temperature hits 55 degrees Celsius, and since the Nitro+ Limited Edition doesn’t get anywhere near that hot except during gaming, the card stays utterly silent during normal desktop use, unlike reference Vega cards. The fans support Sapphire’s Fan Check and Quick Connect initiatives, allowing you to check their health in Sapphire’s Trixx utility and quickly pop out individual fans if one needs replacing.

Sapphire is also introducing “Turbine-X” with the Nitro+ Radeon RX 64 Limited Edition. Turbine-X adds a PWM fan header to the rear end of the card’s custom PCB, similar to what you find on ROG Strix graphics cards that support Asus’ FanControl technology. That header can power up to two case fans, which then take orders from an on-card hardware controller that monitors five temperature sensors on the graphics card’s PCB to ramp fan speeds up and down as needed. Nifty!

sapphire radeon vega 64 nitro le 9 Brad Chacos/IDG

You may have noticed the clear acrylic around the two fans at the card’s extremities. Those house RGB LEDs that can be customized with a new version of Trixx. The Sapphire name on the edge of the Nitro+ Limited Edition glows as well, along with the Nitro logo adorning the card’s full-length backplate. And yes, you can disable the lighting completely if illuminated PC gear gets you grumpy.

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The Nitro+ Radeon RX 64 Limited Edition backplate.

Whew! Sapphire sure stuffed this card with cooling potential, and as you’ll see in the performance section later, it pays off when it comes to the biggest flaws in reference Vega 64 cards.

Sapphire ostensibly engineered this for maximum overclocking potential in case you happen to get a golden Vega GPU, but the Nitro+ Radeon RX 64 Limited Edition ships with a decent factory overclock in place, too. Reference Vega 64 cards ship with a 1,274MHz base clock and 1,546MHz boost clock, though those limits can be exceeded if the card stays cool. The Nitro+ Limited Edition offers 1,423MHz base/1,611MHz boost clocks. That’s halfway to liquid-cooled Vega 64 speeds, which top out at 1,677MHz.

The Nitro+ Limited Edition also offers a secondary “efficiency” BIOS, accessible via a switch on the edge of the card. It’s slightly more conservative than the default clock speeds for reference Vega 64 models, with 1,273MHz base/1,529MHz boost speeds. Of course, you can use the Wattman tool in Radeon Software to shift the card between Vega-specific Power Save, Balanced, and Turbo power profiles, too.

dsc3123 Sapphire

We’re gonna need a bigger PSU.

Speaking of power, you’re going to need an enthusiast-class power supply to run the Nitro+ Radeon RX 64 Limited Edition. Sapphire recommends three 8-pin power connectors and a minimum of an 850-watt PSU. That’s not as excessive as the 1,000W requirement for liquid-cooled Vega 64, but for comparison, Nvidia suggests a 500W PSU for its similarly powerful GeForce GTX 1080, which only requires two power pins. Sapphire’s overbuilding this card a bit though—the third power connector’s mostly there to support high-end overclocking. The card’s power connector circuit includes a fuse protector to keep your hardware investment safe in the event of a power surge.

sapphire radeon vega 64 nitro le 2 Sapphire

Sapphire also changed up the port configuration on the Nitro+ Limited Edition to make it more VR-friendly. While the reference models pack a single HDMI port and a trio of DisplayPorts, Sapphire’s card has two HDMI ports and two DisplayPort connections instead.

Okay, now you know everything there is to know about the Sapphire Nitro+ Radeon RX 64 Limited Edition—except for how it performs in action. Moving on!

Next page: Our test system configuration, game benchmarks begin

At a Glance
  • The Sapphire Nitro+ Radeon RX 64 Limited Edition eliminates Vega's heat and noise issues with the most impressive cooling we've seen.


    • The most effective GPU cooler we've tested
    • Very quiet fans
    • Overclocked and built to overclock more
    • GPU support bracket included


    • Gargantuan size
    • Some coil whine
    • Performs like GTX 1080, priced like GTX 1080 Ti
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