Specifications and Design

We dive into the liquid-cooled version of Vega and find it performs better than expected.

Just a couple of short weeks ago we looked at the Radeon Vega Frontier Edition 16GB graphics card in its air-cooled variety. The results were interesting – gaming performance proved to fall somewhere between the GTX 1070 and the GTX 1080 from NVIDIA’s current generation of GeForce products. That is under many of the estimates from players in the market, including media, fans, and enthusiasts. But before we get to the RX Vega product family that is targeted at gamers, AMD has another data point for us to look at with a water-cooled version of Vega Frontier Edition. At a $1500 MSRP, which we shelled out ourselves, we are very interested to see how it changes the face of performance for the Vega GPU and architecture.

Let’s start with a look at the specifications of this version of the Vega Frontier Edition, which will be…familiar.

Vega Frontier Edition (Liquid) Vega Frontier Edition Titan Xp GTX 1080 Ti Titan X (Pascal) GTX 1080 TITAN X GTX 980 R9 Fury X GPU Vega Vega GP102 GP102 GP102 GP104 GM200 GM204 Fiji XT GPU Cores 4096 4096 3840 3584 3584 2560 3072 2048 4096 Base Clock 1382 MHz 1382 MHz 1480 MHz 1480 MHz 1417 MHz 1607 MHz 1000 MHz 1126 MHz 1050 MHz Boost Clock 1600 MHz 1600 MHz 1582 MHz 1582 MHz 1480 MHz 1733 MHz 1089 MHz 1216 MHz – Texture Units ? ? 224 224 224 160 192 128 256 ROP Units 64 64 96 88 96 64 96 64 64 Memory 16GB 16GB 12GB 11GB 12GB 8GB 12GB 4GB 4GB Memory Clock 1890 MHz 1890 MHz 11400 MHz 11000 MHz 10000 MHz 10000 MHz 7000 MHz 7000 MHz 1000 MHz Memory Interface 2048-bit HBM2 2048-bit HBM2 384-bit G5X 352-bit 384-bit G5X 256-bit G5X 384-bit 256-bit 4096-bit (HBM) Memory Bandwidth 483 GB/s 483 GB/s 547.7 GB/s 484 GB/s 480 GB/s 320 GB/s 336 GB/s 224 GB/s 512 GB/s TDP 300 watts

~350 watts 300 watts 250 watts 250 watts 250 watts 180 watts 250 watts 165 watts 275 watts Peak Compute 13.1 TFLOPS 13.1 TFLOPS 12.0 TFLOPS 10.6 TFLOPS 10.1 TFLOPS 8.2 TFLOPS 6.14 TFLOPS 4.61 TFLOPS 8.60 TFLOPS Transistor Count ? ? 12.0B 12.0B 12.0B 7.2B 8.0B 5.2B 8.9B Process Tech 14nm 14nm 16nm 16nm 16nm 16nm 28nm 28nm 28nm MSRP (current) $1499 $999 $1200 $699 $1,200 $599 $999 $499 $649

The base specs remain unchanged and AMD lists the same memory frequency and even GPU clock rates across both models. In practice though, the liquid cooled version runs at higher sustained clocks and can overclock a bit easier as well (more details later). What does change with the liquid cooled version is a usable BIOS switch on top of the card that allows you to move between two distinct power draw states: 300 watts and 350 watts.

First, it’s worth noting this is a change from the “375 watt” TDP that this card was listed at during the launch and announcement. AMD was touting a 300-watt and 375-watt version of Frontier Edition, but it appears the company backed off a bit on that, erring on the side of caution to avoid breaking any of the specifcations of PCI Express (board slot or auxiliary connectors). Even more concerning is that AMD chose to have the default state of the switch on the Vega FE Liquid card at 300 watts rather than the more aggressive 350 watts. AMD claims this to avoid any problems with lower quality power supplies that may struggle to hit slightly over 150 watts of power draw (and resulting current) from the 8-pin power connections. I would argue that any system that is going to install a $1500 graphics card can and should be prepared to provide the necessary power, but for the professional market, AMD leans towards caution. (It’s worth pointing out the RX 480 power issues that may have prompted this internal decision making were more problematic because they impacted the power delivery through the motherboard, while the 6- and 8-pin connectors are generally much safer to exceed the ratings.)

Even without clock speed changes, the move to water cooling should result in better and more consistent performance by removing the overheating concerns that surrounded our first Radeon Vega Frontier Edition review. But let’s dive into the card itself and see how the design process created a unique liquid cooled solution.

The Radeon Vega Frontier Edition Liquid Cooled Card

The liquid cooled card shares dimensions with the air-cooled card, though without an integrated blower fan, the likeness stops there. The color scheme is reversed, with a yellow brushed metal body and blue accents and illumination. The top Radeon logo and the blue R cube on the end light up in blue, and as I stated on Twitter, I really hate blue LEDs. They are just uncomfortable to my eyes and I know I’m not the only one. Otherwise, the design of this card is just as sexy as the first Vega FE we looked at.

It still requires a pair of 8-pin power connections to run and the liquid cooling tubing and power to the radiator comes from the front of the card. There is plenty of length to the tubing and cabling, allowing for installation in nearly any chassis configuration.

On the back is a full cover back plate with an exposed area for the GPU tach, a set of LEDs that defaults to blue and indicates the GPU workload of the card. The blue on these is particularly piercing…

Internally we have a unique liquid cooler design. On the left is the pump and block covering the GPU and HBM2 stacks and a blue block covering the power delivery on the card as well. Liquid flows in from the top into the GPU block, through the GPU block outlet on the upper right, down through the VRM cooling, around to the far left, and the back out to the radiator.

This unit on the right is part of the diaphragm pump design that makes this card interesting. Think of this is as a flexible reservoir with a high-tension spring to create pressure back into the system. A diaphragm pump works with one-way check valves and reciprocating diaphragm material to create alternating areas of pressure and vacuum. The T-split you see at the top of the primary pump allows the liquid stored in the overflow area to maintain reliable usage of the cooler through the course of natural evaporation of fluid. This is very similar the kinds of pumps used in fish tanks and artificial hearts, likely a more expensive solution than was found on the Radeon Pro Duo or Fury X as an attempt to correct the deficiencies of older generations (noise, reliability).

This kind of cooler design was only made possible by the extended PCB of the Vega Frontier Edition, either by design or as a happy accident. The noise made by this pump is very different than traditional AIO coolers we have used in the office, more of a “gurgle” than any kind of “whine”. It’s more muted than the Radeon Pro Duo or Fury X, that’s for certain.