Cornering The Mainstream? AMD Debut The Radeon RX 470 & 460

👤by Tim Harmer Comments 📅29.07.2016 05:17:48

Today marks the first public outing of AMD's latest 4th Generation GCN 'Polaris' GPUs. A follow-up to the Radeon RX 480 launch not all that long ago, the two new GPUs continue AMD's current strategy of targeting the mainstream of PC gaming over the highly expensive premium enthusiast market. China's Digital Entertainment Expo and Conference, or ‘ChinaJoy’, has been chosen as the venue for this unveiling, highlighting the importance AMD places on affordable PC gaming and eSports in the gaming nation famed for favouring this approach.

According to AMD up to 84% of discrete graphics owners purchased cards within the $100 to $300 market, a segment which has been crying out for major advances in performance in the past three years. The size and potential this market represents is huge, and the red team were able to capitalise early thanks to the thus-far successful Radeon RX 480 near the top of that particular price bracket. Rather than take Polaris to the upper echelons of the segment - something which will no doubt be achieved by partner boards of the 8GB RX 480 with variant cooling - AMD turns it attention to the <$200 market with the Radeon RX 470 and RX 460.

Today we can reveal details of the Radeon RX 470 and RX 460, the pair of cards that round out the mainstream gaming market whilst focussing on two distinct demographics.

Radeon RX 470

The Radeon RX 480 was launched earlier this month as the first card based on the Polaris architecture, in this case a fully-fledged Polaris 10 GPU with a total of 36 Compute Units, up to 8GB of GDDR5 memory clocked at 8Gbps, and AMD’s full array of graphics technologies. It is AMD's current entry-level VR card and is equipped for high performance gaming up to 1440p; the Radoen RX 470 is a little more modest perhaps - though not by much as it turns out - and could be very attractive for the mainstream gamer.

From a demographic perspective, the Radeon RX 470 targets the vast majority of PC gamers still running games at 1080p whilst offering them very high quality graphics settings and steady 60fps gameplay. Hard-nosed enthusiasts may turn their nose up somewhat but everyone should be clear that performance is expected to be significantly better than the R9 270, the card it ostensively replaces within AMD’s product stack. Major performance improvements - in this case AMD are projecting 1.5x to 2.4x performance boosts depending on game - are exactly what this mainstream segment needs, even at this now veteran resolution.

As for the technical details, RX 470 is based on the Polaris 10 ‘Ellesmere’ GPU, but is the slimmer sibling of the RX 480. Just four Compute Units have been shaved off the RX 470’s Polaris 10 GPU, leaving it with 32CUs rather than 36 (or to put it another way 2048 total shaders). The memory bus remains the same 256-bit width, and combined with memory clocked at 6.6Gbps the card has a memory bandwidth of 211 GB/s. The reference design calls for 4GB GDDR5 VRAM, emphasising a focus on 1080p with high/ultra texture quality over 1440p, VR and 4K.

Radeon RX 470 is clocked at 1206MHz / 926MHz Boost/Base, but note that AMD’s clock speeds tend to be highly variable by virtue of their dynamic load balancing, so really they’re a guideline only. AMD's methodology is known to benefit significantly from high quality cooling, offering board partners the opportunity to really push the design limits.

The reference specifications outline an expected TDP of 120W, which was slightly higher than pre-release expectations of 110W. It’s possible, even likely, that AMD are being highly conservative with their TDP ratings given the fallout over the RX 480’s higher than anticipated power draw, either way its well within the 150W limitations imposed by a single 6-pin PCI-E power connector.

Radeon RX 460

In contrast to the RX 470 the Radeon RX 460 utilises a brand new GPU, the smaller Polaris 11 ‘Baffin’ model. Once again this is a 4th generation GCN chip incorporating the latest AMD technologies, but in a much more low-power budget package. As a result it's really intended for entry-level gaming with a discrete graphics card, offering superior performance at 1080p in a wide range of the most popular online titles. Where the RX 470 is for the eye-candy, the RX 460 gets you in the game and having a great experience for as little money as possible. That's the theory anyway.

The Polaris 11 'Baffin' in use by the RX 460 is equipped with 14 Compute Units (864 shaders), rather than what’s understood to be a full potential complement of 16CUs on the Baffin GPU. Given that the card is skirting the critical 75W TDP mark it's likely been narrowed down in order to keep the card under control power-wise whilst maintaining high clocks.

Speaking of clock speeds, the RX 460 runs at 1200 / 1090 MHz Base/Boost, essential figures to push polygons at relatively low resolutions. A 128-bit memory interface is appreciably narrower than AMD's larger models, but memory clocked at 7Gbps will compensate for reduced bus width. Nonetheless the card may not be able to turn on all the trimmings in most modern games, but will still provide an excellent experience.

Compared with the R9 260X the RX 460 is a smooth operator, offering >20% performance improvement than its predecessor in a wide range of titles at preferred IQ settings. That's certainly getting into the realms of 'worth upgrading' value, and will be a major boost over both integrated APU graphics or aged mainstream cards still in circulation.

Oh, and one further titbit: RX 460 explicitly only makes use of eight PCI-E 3.0 lanes (although it populates an x16 slot for compatibility reasons).

The Benefits of Polaris

As 4th Generation GCN parts the entirety of the RX 400-series don't incorporate the inherent advantage of the smaller production processes which has made this generation of cards so energy efficient compared to their predecessors. Each also features AMD's bevy of technologies that makes 4th Gen GCN such an attractive proposition.

The highlight has to be GCN's DirectX 12 and Vulcan support. Both GPU vendors can benefit from Microsoft and the Kronos Groups' low-level graphics APIs, but AMD have stolen a march thanks to heavy optimisation for Asynchronous Compute. The robust architecture with comprehensive hardware scheduling support has meant that even extending earlier into GCN generations the hardware is well capable of leveraging the performance of this advanced feature.

Async. Compute will get the headlines, but additional improvements under the hood make the GPU a further step ahead of the last generation.

- Memory delta compression has been improved, increasing effective memory bandwidth against the 200-series cards by up to 35% (depending on workload)
- Geometry engine improved, adding a primitive discard accelerator and small geometry index cache. The former will improve MSAA performance, the latter more general throughput
- Improved Shader Efficienty with native FP16 & Int16 support.
- High Dynamic Range support
- 2-pass encoding for video (supported by OBS, PlayTV and Gaming Evolved App
- HEVC video codec
- Shader support for VP9 video encoding

Furthermore, all the RX 400-series is backed up with a new overclocking utility known as Wattman, offering more comprehensive options and control. That means assuming suitable cooling and power delivery even the budget RX 460 could have a little (or even a lot) more performance squeezed out of it by keen and frugal users.

AMD CrossFire? Of Course!

All three members of AMD’s Polaris GPU family support AMD CrossFire multiGPU technology. AMD continue to use ‘bridgeless’ XDMA communications between GPUs over the PCI-Express bus, which offers superior and scalable bandwidth compared to their bridged implementation prior to the 7000-series. The RX 480 and 470 are both capable of up to 4-way CrossFire, whilst the RX 460 can be configured in 2-way CrossFire configurations.

In addition to CrossFire the new cards also support implicit and explicit Multi-GPU modes for DirectX 12.

Going Mobile – Radeon RX Branding For Notebooks

Alongside the announcement of the RX 460 and 470, AMD have also teased the upcoming GPUs we should be expecting within new gaming notebook lines. These notebooks will carry the Radeon RX 460 branding and feature the same RX 460 GPU as the desktop model, reducing customer confusion at a stroke by dispensing with the 'M' moniker.

This has been made possible thanks to the reduced power requirements of GPUs built with GloFlo’s 14nm process compared with the older TSMC 28nm silicon. As a result you get considerably more bang for your buck without needing expensive additional cooling and augmented power bricks.

Let The Partners Have Their Fun

Whilst reference specifications for each of the new cards have been outlined, not AMD reference design will be sold through retail channels. Instead only partner models will be on the market, which is in sharp contrast to the launch of the Rx 480. As a result bespoke PCBs and coolng designs will be the norm rather than the exception, including factory overclocks and proprietary technologies unique to each vendor. Potentially we will also see RX 470 models with 8-pin PCI-E or 460 with 6-pin, each accounting for higher than usual power draw due to augmented overclocking support.

Price and Release Date

You won’t have to wait long on the Radeon RX 470 and 460. The former is due to be available on August 4th, whilst the 460 will be on shelves four days later (August 8th).

Unlike the launch date, pricing remains a little more uncertain. Official price guidance has yet to be released on either card as of the time of writing, but it is obvious that they will be released within the $100-$199 window (placing both below the RX 480 4GB). The cost of individual models are however likely to be highly variable anyway due to each being a board partner’s interpretation including the use of high-end cooling solutions.

The release of both cards is also likely to coincide with that of partner versions of the performance-class Radeon RX 480, featuring augmented power infrastructure and cooling.

Expect reviews for both cards on the date of launch, and pay very close attention to them. If AMD can really offer substantially improved performance at this price point its great news for budget and mainstream PC gamers.