AMD Radeon R9 Fury X – Compact Powerhouse
During E3 PC gaming show, AMD has announced their “new” graphics card line-up – Radeon Rx 300 series. Unfortunately, for many enthusiast gamers, these are just rebrands of HD 7000 and Rx 200 cards. There are some higher factory clocks and 8 GB of VRAM as a welcome default option on 390 and 390X. Not a large push forward from an year and half old parts, while also increasing the prices of some of their successors. Fortunately, there is also something new and technically exciting – several R9 Fury cards.
Fury X is the most powerful single GPU card AMD has at the moment and it has already been released. It is unique in many ways as well. To start with, it no longer uses GDDR5, but a stacked high bandwidth memory (HBM). While memory is clocked lower than GDDR5, it consumes less energy and is connected to the GPU using 4096-bit wide memory bus giving the impressive 512 GB/s bandwidth (290X has “just” 384 GB/s). The memory bus is so massive that it is no longer made on a board itself, but inside a large interposer chip. Both GPU and memory are placed very close to each other on this interposer. Unfortunately, due to the currently available HBM chips and the size of GPU, Fury X only has 4 GB VRAM. The reduction in memory power consumption, allowed AMD to build a very large GCN 1.3 based GPU, codenamed “Fiji”, without making the whole card consume too much power. Fiji is the largest GPU AMD has ever built, consisting of nearly 9 billion transistors on 596 mm2 chip, arranged into 4096 cores (45% more than 290X). The card can consume up to 275W and costs $650.
To both keep this monster cool and reduce power waste, AMD has made Fury X to be liquid-cooled only, while only slower Fury is going to be air-cooled. As a result, Fury X looks very different from outside. The card is just 194 mm long and has no fan at all (unlike 295X, which needed one to cool VRAM separately). With no need for air circulation, there are no grilles on the back, and the whole card is completely closed in black shroud. However, you will have to find a place for a 120 mm radiator and fan somewhere in your case, to cool the liquid coolant. The port selection may be another issue for some. Fury X has 3 DP 1.2a ports and a single HDMI 1.4 port. While the lack of DP1.3 is understandable, due to the freshness of the standard and lack of DVI can be fixed with a dongle, lack of HDMI 2.0 is a problem for people who want to play on 4K TVs. There are no dongles from DP 1.2 to HDMI 2.0 yet, while Nvidia has been supporting HDMI 2.0 for over 8 months.
In terms of performance, Fury X manages to outperform 290X by 20 –30% on average. A decent result, considering the similar power draw, while still being built using 28 nm process. Unfortunately for AMD, Nvidia has released a much more dangerous competitor few weeks before – GTX 980 Ti. In most games, Fury X falls around 10% behind similarly priced Nvidia’s card. Additionally, GTX 980 Ti also supports DX feature level 12_1, compared to Fury’s 12_0 (although Nvidia still doesn’t support some DX features, AMD has supported since HD 7970), has more VRAM (6 GB) and HDMI 2.0 output for people playing on 4K TVs. On AMD’s side there is a more effective and silent liquid cooler included in the price, although it requires more space elsewhere in the case.
The amount of VRAM is an issue as well. With the ~5 GB of usable unified RAM in modern consoles and the rising popularity of 4K gaming, having as much VRAM as possible is important for the high-end card. AMD clearly understands that and that is why they equipped 390 and 390X with 8 GB. Regrettably, the technical limitations stopped then from doing the same with Fury. While 4 GB is still enough for many games, it is a lower bound for a comfortable 4K experience and 6 GB in 980 Ti is much safer, while 12 GB in Titan X is certainly enough if you have money to burn.
Overall, AMD Radeon R9 Fury X is a very interesting card from a technical standpoint, but a hard purchase to justify for its price. HBM and similar 3D memory configurations are clearly the future and Nvidia plans to implement 3D memory on their future GPUs based on Pascal architecture. While HBM has not shown its full potential in Fury yet, the experience may help AMD with their future GPUs based on a more compact process. Other interesting things to watch for will be R9 Nano and R9 Fury. Based on somewhat cut down Fiji, those cards will be air-cooled, while Nano should be a small, lower power card, matching or beating R9 290X performance. Depending on how well they perform, they might find a much more comfortable niche, rather than the direct confrontation against 980 Ti.