A Partner Launch: No Reference Cooler

This is a partner launch. There is no “reference” card this time around, despite rumors proliferated by less scrupulous websites, and there will therefore exist no reference cooler. Despite promises by some sites that the RX 500 cards would include dual axial fan coolers, that’s not what reality promises. AMD’s Scott Wasson (who visited us to talk VR benchmarking and other topics) noted that the RX 500 series is focused on AMD’s board partners, and so those partners will be responsible for cooling solutions.

That cleared up, here’s a look at the new specs table:

The difference with the 500 series is effectively a pre-overclock, with some power tuning for low-load & idle tasks. The RX 580 and 570 cards ship with a higher native clock than previous reference clocks (and higher than most previous AIB partners), with additional OC headroom afforded through new voltage budget increases. Voltage can now be incremented an additional 25mV via Wattman, providing a total of 1200mV via the utility, plus whatever offset the board partners provide. In the case of MSI, we can get up to 1.256v on the MSI RX 580 Gaming X board, allowing a higher stable OC than the RX 480 card. We’ll look at our OC stepping table a bit later.

There’s a bit of a dichotomy in power behavior with the RX 500 series: More mature process means better efficiency, aided in some ways by nondescript “fine-tuning” done by AMD. These efforts bring the RX 500 series cards down in idle power consumption and low-load power consumption (like video playback). Naturally, power draw also increases at the high-end of the scale, as the higher frequency and voltage drink more from the wall. Power draw gets worse toward the top-end of the volt-frequency curve, given usual leakiness at the high-end, but tend to be better than the 400 series at the absolute low-end of that same curve.

For prices of the RX 500 series, here’s what we’ve got so far:

ASUS

• $189 for RX 570 STRIX OC 4GB
• $179 for RX 570 STRIX 4GB

Gigabyte

• $259 for RX 580 Aorus OC 8GB
• $229 for RX 580 Aorus 8GB
• $219 for RX 580 Gaming 8GB
• $199 for RX 580 Aorus 4GB
• $189 for RX 580 Gaming 4GB
• $179 for RX 570 Aorus 4GB
• $169 for RX 570 Gaming 4GB

MSI

• $245 for RX 580 Gaming 8G
• $229 for RX 580 ARMOR 8G
• $199 for RX 580 ARMOR 4G
• $175 for RX 570 ARMOR 4G

Sapphire

• $275 for RX 580 Nitro+ Limited edition 8GB
• $249 for RX 580 Nitro+ 8GB
• $229 for RX 580 Pulse 8GB
• $209 for RX 580 Pulse 4GB
• $199 for RX 570 Nitro+ 4GB
• $169 for RX 570 Pulse 4GB

TUL

• $269 for RX 580 8GB Red Devil Golden Sample
• $249 for RX 580 8GB Red Devil
• $229 for RX 580 8GB Red Dragon
• $199 for RX 580 4GB Red Dragon
• $175 for RX 570 4GB Red Dragon

We’re working with the MSI RX 580 Gaming today, priced at $245. For our core competing product, we’ll be re-testing the EVGA GTX 1060 SSC (priced at $240-$250 – i.e. equally). Some of the charts will allow an MSI 1060 Gaming X to pop-up, but it’s primarily between the RX 580 Gaming & EVGA 1060 SSC cards. We’ve got the RX 480 Gaming X on the charts as well, since it’s worth seeing whether the 580 posts any meaningful improvement over an overclocked 480.

For what it’s worth, we’ve also got a $250 XFX GTR unit and will review that posthaste. Our RX 570 is the Aorus 4GB model, priced at $180. The new price floor for the RX *70 series seems to be ~$170, continuing AMD’s already-competitive positioning against the 1050 Ti.

Refresher on Polaris Architecture 

If Polaris is new to you – or if it’s just been a minute – here are some content pieces from the architecture’s debut:

• RX 480 Architecture & Review
• RX 470 Review

To recap the basics, we’ll quote the first article:

“AMD has coupled its FinFET process with datapath organization improvements and improved data compression, both of which reduce overall power consumption. Memory alone has seen an energy reduction upwards of 40% per bit transacted, significantly lowered versus Hawaii and previous generations. This allows more room for energy provided to the cores, of course, but also reduces total consumption. Changes to boosting functions have also improved power utilization, mainly by introducing 7 DPM states (DPM1=sleep, DPM7=fully unlocked for high-end production/gaming).

“Clock gating and power gating for under-utilized circuits furthers the perf/watt argument, as does the introduction of heuristic pre-fetch routines that keep cycles occupied with instructions.

“But that's getting ahead of the architecture discussion.

“Packed into the RX 480 Polaris 10 chip is a grouping of 36 CUs, over which rests a single GCP (Graphics Command Processor), flanked by two Hardware Schedulers (HWS) and four Asynchronous Compute Engines (ACEs). Polaris 10 and Polaris 11 both operate on a single GCP and have expanded reliance upon the HWS over what was found in Gen 3 GCN. The HWS block was first introduced on Gen 3, and owners of Fury- and 390-class GPUs will be happy to know that microcode updates to firmware will enable some of the Polaris-class HWS enhancements. One of those is the introduction of QRQs, which aid in hardware power reductions when using the Oculus Rift HMD. The HWS is controlled by microcode and can be updated through drivers, beneficial as hardware and APIs mature.

[…]

“One of the RX 480's biggest changes is its doubling of L2 Cache. With more capacity in cache for data storage, texture references and color compression remain resident for longer (reducing computational workload). This improves processing efficiency and reduces bandwidth consumption where unnecessary. There's no reason to transact the same data back-and-forth if it can be stored into a local, nearby cache.

“Critically, this also has a side effect which is perhaps overlooked: Energy savings. Along with the power reduction native to smaller FinFET process nodes – moving away from planar helps tremendously – the caching system reduces power consumed by GPU memory. Delta Color Compression (DCC) and 2MB of L2 Cache work in conjunction to minimize VRAM activity, and while it is impossible for us to test something this low-level at GN, AMD tells us that power savings are upwards of 40% on memory transactions alone.”

To read the rest on Polaris architecture, check page 1 of our original review.

MSI RX 580 Tear-Down 

The MSI RX 580 Gaming is trivial to tear-down. It’s a couple screws in the back-side to secure a thermally functionless backplate to the card (if anything, it’s there for structural support), then four screws to release the finstack. Flipping the card over, three cables are responsible for fan and LED connections, with another two screws mounted into the backplate.

Under all this, an inscriptionless die is revealed and flanked by Samsung memory modules (K4G80325FB-HC). OnSemi M3816N power stages are used as part of the 6-phase VRM.

Before the Tests: Overclock Stepping 

Before getting into power, thermals, and gaming benchmarks, we should probably show our work for overclocking. The charts will refer to an RX 580 “OC” – the below is what we’re talking about:

(Max power draw peaked at ~290W for the above).

The RX 480 Gaming X got stuck around 1365-1375MHz with its more limited 1175mV offset.

For the GTX 1060 SSC, this is what we ran with:

Enough of this first page.

Continue to Page 2 for GPU test methodology.