Wednesday, 29 June 2016

AMD's Radeon RX 480 Benchmarked: Par For The Course

The amount of hype behind AMD’s Polaris-based line of graphics cards has been nothing short of monumental. It’s not hard to see why: when you promise a VR-ready card that only costs $US199/$US229, people are bound to get excited.

But when you put the card through its paces, does it live up to the hype? That depends on your expectations.

Image: Supplied

The jump from the previous generation of graphics cards has been a long time coming. And there’s good reason to be excited: if you’re an owner of the R9 200 or 300 series cards, Polaris offers an immense jump in power efficiency, performance per watt, more headroom for clocking, quieter GPUs and, most importantly, faster GPUs.

But precisely how faster are we talking? That will be the sticking point for a lot of gamers. Those expecting the RX 480 to compete on any sort of platform with NVIDIA’s GTX 1080 or even the 1070 — don’t bother, because that’s not what the card is built for.

Straight out of the box — or bubblewrap, as it was sent to us — the RX 480 is more of a natural replacement for the R9 390 series in performance. It’s also a serious competitor to NVIDIA’s GeForce GTX 980: the cheapest 980 at the time of writing is $628, and once stock of those run out you’ll have to fork out $700 or more.

In comparison, 8GB models of the RX 480 are going for as low as $379. If you’re looking for a card that can handle virtual reality without breaking the bank, and you’re not expecting stratospheric levels of performance, the RX 480 is a good place to start.

Base Specifications

Built on the 14 nanometer FinFET semiconductor process, the RX 480 has a die of 232 mm2 and comes in two reference versions: a 4GB card with 7Gbps GDDR5 memory, a 256-bit memory interface, a core clock speed of 1120 MHz with a boost speed of 1266 MHz, and peak performance of up to 5.8 teraflops. There’s support for DirectX 12, the Vulkan API, DisplayPort 1.3 and 1.4, as well as 36 compute units and 2304 stream processors.

The 8GB reference model has largely the same statistics, but with 8Gbps of GDDR5 memory instead of 7Gbps, and a memory bandwidth speed of 256GB/s instead of the 4GB’s 224GB/s.

For the RX 480 specifically, here’s a full list of the card’s specs straight from the free-to-use GPU-Z utility.

All tests were conducted on the beta Crimson 16.6.2 drivers which were supplied by AMD. It wouldn’t be unreasonable to expect some improvement in performance as AMD continues to iterate on their drivers

Here’s the specifications for our benchmarking machine:

CPU: Intel Core i7-4790K @ 4.0GHz
RAM: 16GB Corsair Dominator DDR3-RAM @ 1600 Mhz
GPU: MSI R9 390X Gaming 8GB
PSU: Corsair HX850i 850W
HDD: Samsung 850 EVO 1TB SSD
Motherboard: ASUS Z97I-PLUS Mini-ITX (Intel Z97)
Keyboard: Cherry MX 3.0 Mechanical Keyboard
Mouse: ZOWIE FK2
Headphones: Audio Technica ATH-M50x

All figures shown are averaged out over three runs.

A staple as far as synthetic benchmarks go, 3D Mark’s Fire Strike demo pushes computers and their graphics cards to the limit. They’re often the first benchmarks you’ll see whenever a new GPU is released. It’s not wholly indicative of what a card’s real-world performance will be like, but it does provide a reliable indicator of the performance between cards

The RX 480 was never expected to be anywhere near the GTX 1080 when it came to single-card performance, but it’s an interesting comparison point for those considering running two RX 480’s in Crossfire. The much more helpful reference point here is against the MSI R9 390X.

In the base level Fire Strike test, the 390X is just over 11% faster than the Polaris-based RX 480. That gap widens to more than 12% in Fire Strike Extreme, and when the rendering resolution is upped to 4K for the Fire Strike Ultra test, the 390X is around 13.6% quicker.

On the surface, that seems a touch disappointing. But it’s actually reasonable when you consider the RX 480’s starting price, and the additional headroom it has for overclocking. People should also consider the fact that partner boards are likely to have even better performance, and it wouldn’t be unheard of for AMD to squeeze a bit more real-world performance out of the card down the road

It’s here where the gap between the RX 480 and the 390X starts to become more prominent, but the RX 480 still manages to achieve an admirable frame rate of 76.1fps in 4K.

The distance at all resolutions is noticeably higher than the 3D Mark results, with the 390X around 28 to 29% faster at all resolutions. That said, it’s an area where AMD can affect the most going forward with future driver updates. And it’s also worth remembering that The Talos Principle was tested using DirectX 11. Its Vulkan support is still pretty rudimentary, and the value of the RX 480 — and the Polaris line in general — supposedly shines the brightest in DirectX 12.

So let’s see how that plays out.

A better benchmark than a game, Ashes of the Singularity has been one of the most comprehensive DX12 benchmarks since even before its launch in Early Access. AMD cards have also been known to punch well above their weight in Ashes, as can be seen with the RX 480’s performance against the more powerful GTX 1080.

The Extreme preset with 4X MSAA was used for all resolutions, and the average fps is displayed below.

The distance between the RX 480 and the GTX 1080 certainly isn’t several hundred dollars. The gap between the RX 480 and the R9 390X is pretty minor too.

It’s not unfair to say that the RX 480 is more or less a direct replacement in performance for the R9 390, but with all the trimmings of less heat, less noise and more headroom for overclocking.

Vulkan support for DOOM still hasn’t arrived, and doesn’t look like it’s likely to over the next week. But no matter: the game’s performance in OpenGL is pretty stellar nonetheless. The RX 480’s performance is pretty respectable as well, hovering just a few percent underneath the R9 390X and only fractionally off the magical 60fps mark in 1440p.

Average frame rates are shown below, with the Ultra preset, FXAA (1x) and chromatic abberation enabled. All runs were conducted by running through the game’s third mission, Foundry, on the Ultra Violence difficulty for two minutes. No enemies were killed to ensure consistency with the amount of bodies being rendered and encountered, although slight differences occurred from run to run (such as the enemies opt to beat the snot out of each other).

With no adjustment to the stock speeds, the RX 480 more or less mirrors the R9 390X’s performance here across all resolutions. It blows out to around 12% at 2K, being able to hit 60fps at Ultra (and more on the lower presets) will make a lot of gamers pretty happy.

As part of the Polaris launch, AMD has bundled a new set of overclocking tools into the Catalyst driver suite. It’s called WattMan, and it’s accessible through the Gaming tab of the AMD Radeon Settings control panel. All 400 series cards will support the new overclocking software, but it’s not currently known whether support will also be extended to the 200 or 300 series.

The suite allows users to track peak and average fan speeds, GPU and memory speeds, temperature, and the GPU’s level of activity. WattMan also provides a histogram for tracking, and users can set individual overclocking profiles for specific games.

To overclock, users can either the GPU clock frequency slider in 0.5% increments, or they can set individual MHz targets across various stages. The GPU’s voltage control can also be adjusted manually if desired. It’s worth noting that the power limit feature for the temperature control, which can increase or lower the amount of power sent to the card, is specific to cards with the Polaris 10 XT core (so only the RX 480 for now).

I upped the core clock speed to 1330 MHz, the memory speed to 2050 MHz and allowed for an extra power to be sent to the GPU. I then ran the 3D Mark Fire Strike again, and the RX 480 maintained all the set limits without taking off like a jet engine (the drop downs are the loading times in between Fire Strike’s graphics/physics/combined tests).

From the testing I was able to do prior to embargo, there’s no reason why most users can’t at least squeeze an additional 100 MHz out of the GPU clock. But it’s worth noting that you don’t have a great deal of headroom in the temperatures. At stock settings the card idled at around 48oC, but under heavier loads (like when running 3D Mark, or something at 4K) temperatures will hover in the 70oC to 80oC range.

That’ll be a bit of a disappointment to users who were hoping to push the RX 480 further. But then again, we’re only dealing with the reference card here. Custom versions, particularly watercooled ones, could really eek out some value from AMD’s new Polaris GPU, although we won’t see those for months.

So that’s how the 14nm Radeon RX 480 from AMD, the card that so many have been so excited about, stacks up in the real world. It’s a solid performer at 1080p and 1440p. Hell, to have a card that can competently play titles at 1440p with the visual fidelity of DOOM while maintaining 60 FPS is an impressive achievement.

And if you can snag a RX 480 for under $400, that’s not an unreasonable deal.

But. As a reference board, the RX 480 doesn’t have a great deal of room for improvement. It runs pretty hot. And out of the box, it doesn’t surpass the R9 390 or 390X like some fans were hoping.

So we get back to expectations. The main line AMD promoted was that the RX 480 would be a VR ready card for $US199, although the slightly more expensive 8GB model is really what most people are interested in. And if you’re only looking to play at 1080p or 1440p, the RX 480 will get you there.

The thing is, the R9 390X is in the same territory — and if it’s possible to snag one up for cheap, it might be hard to pass up a deal. But the RX 480 doesn’t use anywhere near as much power, is quieter and doesn’t run quite as hot. It’ll really get interesting for a month or two until we see custom designs from AMD’s partners, designs that can cool the RX 480 a little better.

So is the RX 480 a good deal? That depends on what you were expecting. For some: definitely. But the RX 480 most certainly isn’t a giant killer. It’s more like the new par for the course, which isn’t so bad when you think about it.

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