Introduction

The one genre of games that kept the PC alive as a mass-gaming platform in the wake of reasonably powerful new-generation consoles is MOBA, and there are the other multiplayer genres that make up today's e-Sports scene, which is meeting as much commercial success as sports in general. One of the key characteristics of these MOBA games is their playability on entry-thru-mainstream graphics hardware. Some of these even work on integrated graphics, though with low details, and quite a few can be maxed out at 1080p with sub-$200 graphics cards. AMD's bottom-up approach to this generation of consumer graphics cards with its Radeon RX 400 series is now addressing this segment with the new Radeon RX 460.

Priced at just $109 (MSRP), this card draws console gamers over to the PC platform, letting them convert their drab Dells to 720p gaming machines since they can't exactly master MOBA games on consoles with their input limitations. The card relies on the PCI-Express slot for all its power and can hence be installed into any machine with a PCI-Express slot, although ASUS (the card in this review) didn't pledge its reputation on that and went ahead with giving this card an additional 6-pin PCIe power connector. Its power draw is under 75W, which means practically any OEM desktop power supply has the juice for it.



The Radeon RX 460 is based on AMD's second silicon implementing, its "Polaris" architecture, and bears the ASIC codename Polaris 11 "Baffin". This chip is tiny thanks to the 14 nm FinFET process it's built on. The chip features 896 stream processors, 56 TMUs, 16 ROPs, and a 128-bit GDDR5 memory interface, holding either 2 GB or 4 GB of memory, which has it address two key sub-$150 price-points. You get most of the feature introduced with this generation, including modern display connectivity support.

In this review, we have with us the ASUS Radeon RX 460 STRIX, featuring a simplified version of the company's DirectCU II cooler, 4 GB of memory, and a factory-overclock. The card features a price tag of $139; its 2 GB variant is expected to be priced at $109.

Architecture

The Radeon RX 460 is driven by AMD's second silicon to implement the "Polaris" architecture, codenamed "Baffin." This is a tiny GPU owing to AMD using the 14 nanometer FinFET silicon fab process by GlobalFoundries. The wafers are made in Upstate New York, USA, and are then bumped and packaged at a facility in Taiwan to be sent to the various graphics card manufacturers located there and across the straits.



This GPU is based on AMD's fourth generation Graphics CoreNext architecture codenamed "Polaris." According to AMD, Compute Units (CUs) based on Polaris are 15% more efficient at number crunching than CUs based on the preceding Graphics CoreNext 1.2 architecture (R9 Fury, R9 380X). Pay attention to the numbers here. While the number-crunching machinery is 15% more efficient, the chip is claimed to have a 2.5x leap in overall energy efficiency over the previous generation. This is because AMD is cashing in on the immediate gains a new silicon fab process brings to the table, the 14 nm FinFET process in this case, to increase transistor counts and clock speeds.



The component hierarchy in the Polaris 11 "Baffin" silicon is similar to older-generation chips, although each of the components received major updates. We begin with the chip featuring two hardware schedulers and the introduction of dedicated real-time asynchronous compute with spatial and temporal scheduling. The chip also features async compute engines (ACEs). AMD optimized the async compute engine with new quick-response queue tech.



There's a design focus on stepping up geometry processing performance and blunting the brute-tessellation advantage NVIDIA traditionally enjoyed over AMD. For a chip of this segment, Polaris 10 features four independent geometry processors. Their functionality is upgraded over the previous generation, featuring a primitive discard accelerator which culls (discards) triangles in the pipeline with zero area or no inclusive sample points. The geometry engine now features a tiny cache called the Index Cache, which cushions small instanced geometry and reduces data movement to improve primitive throughput during instancing.

The Polaris 11 silicon features 14 Compute Units (CUs) spread across two shader engines, each with a dedicated geometry processor, a raster engine, and two render backends. The two shader engines are supported by an L2 cache, which acts as the town-square for the GPU's various key components.

Most of the architecture-specific innovations are centered on the CU, which now features a hardware instruction prefetcher, a larger instruction buffer, and native half-precision (FP16/Int16) support, which should reliably crunch numbers for gaming applications with significantly reduced memory and register footprints while lowering power execution. Altogether, the "Polaris" CU is claimed to have up to 15% higher performance than CUs based on the GCN 1.1 architecture (R9 390X). Each CU features 64 stream processors, which has the 14 CUs amount to 896 stream processors. In summary, the Polaris 10 chip features 896 stream processors, 56 TMUs, and 16 ROPs.



The Radeon RX 460 features a 128-bit wide GDDR5 memory interface, holding 2 GB or 4 GB of memory clocked at 7 Gbps. The actual memory bandwidth of this interface at its given clock speeds is rated at up to 112 GB/s, although its effective bandwidth could be higher thanks to an updated lossless delta color compression (DCC) tech with full 2/4/8:1 compression ratios. AMD claims that its new gen DCC tech can provide an effective bandwidth uplift of a staggering 30 percent. The ASUS Radeon RX 460 STRIX we're reviewing today features 4 GB of memory.



The multimedia accelerators receive a major update, now supporting H.265 Main10 decode hardware acceleration and 4K60 HEVC encode hardware acceleration. The other components with big updates are the display controllers, which now support DisplayPort 1.4 (DP 1.3 HBR3 and DP 1.4 HDR) and HDMI 2.0b. FreeSync is supported over both DP and HDMI. Resolutions as high as 5K60, 10-bit 4K96 HDR, and 4K120 SDR are supported.

Packaging

You will receive:

• Graphics card
• Driver CD + documentation
• ASUS zip ties
• ASUS stickers

The Card

ASUS is using the same cooler shroud as on their RX 470 for the RX 460, but under the hoid, the cooler is different. It is dominated by plastic and has no colored highlights. Some stickers are included in the package, so you can put them on if you prefer some color instead of the all-black theme. Dimensions of the card are 24.5 cm x 13.0 cm.


Installation requires two slots in your system.


Display connectivity options include one DVI port, one HDMI port, and one DisplayPort.

The HDMI port is now version 2.0b, and DisplayPort has been updated to 1.3 HBR3/1.4 HDR ready, which enables support for 4K @ 120 Hz and 5K @ 60 Hz, or 8K @ 60 Hz with two cables. GPU accelerated encoding is now supported for H.264 at up to 4K30, and HEVC is supported at up to 4K60. Accelerated decoding is supported for HEVC at up to 4K60 Main-10, VP9 is supported at up to 4K, and H.264 works at up to 4K120.


AMD CrossFire has been running over the PCI-Express bus for a few generations now. The Polaris Series is no different.


Pictured above are the front and back, showing the disassembled board. High-res versions are also available (front, back).