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Radeon R9 290X Review: AMD's Back In Ultra-High-End Gaming

Radeon R9 290X Review: AMD's Back In Ultra-High-End Gaming
By , Igor Wallossek

After eight months of watching Nvidia go uncontested in the ultra-high-end graphics market, AMD has a new GPU based on existing technology that promises to challenge the top position. It gets mighty loud at times, but you can't ignore the R9 290X's price.

Today, the fastest single-GPU graphics card is Nvidia’s GeForce GTX Titan (Benchmarking GeForce GTX Titan 6 GB: Fast, Quiet, Consistent). It sells for no less than $1000 and comes equipped with 6 GB of fast GDDR5 memory. By all accounts, it’s really well-suited for gaming at 2560x1440, it serves up playable performance at 5760x1080 in some games, but doesn’t quite move fast enough for 3840x2160. In fact, in Gaming At 3840x2160: Is Your PC Ready For A 4K Display?, I came to the conclusion that it’d take a couple of GeForce GTX 780s to serve up satisfactory frame rates on an Ultra HD screen.

And now AMD is billing its new Radeon R9 290X as a ready-for-4K solution. Them’s fighting words, particularly with Ultra HD targeted as the next frontier in PC gaming. The technology is still very expensive, and it’s far from refined. But I challenge you to enjoy your favorite title on a 32”, 8.3-million-pixel screen, and then hand it back willingly. Expect 4K to be the battleground on which AMD and Nvidia drop their high-end GPUs moving forward.

Last week, while Nvidia put on an event in Montreal to announce a handful technologies and initiatives, including an upcoming GeForce GTX 780 Ti, AMD was taking the wraps off of a few benchmark results that indeed showed the 290X faster than GeForce GTX 780 in BioShock Infinite and Tomb Raider at 3840x2160.

What is at the heart of this new board, which seemed to effortlessly speed past Nvidia’s $650 solution? The Hawaii GPU—a much more complex piece of silicon than Tahiti, based on the same Graphics Core Next architecture. Think of it as a little bit of old and a little bit of new.

Is AMD Back To The "Big GPU" Approach?

All the way back in 2007, AMD altered its GPU strategy, shifting away from large monolithic processors in favor of more scalable designs. It’d build for a fairly mainstream price point/power target, and either derive down to create less expensive parts or stick two GPUs next to each other in an ultra-high-end configuration.

Over time, AMD’s engineers trended toward more complex chips, and the ~100 W RV670 gave way to the 150 W RV770, which was succeeded by the Radeon HD 5870’s roughly 200 W Cypress GPU, the 6970’s 250 W Cayman, and the similarly power-hungry Tahiti. Each step of the way, though, AMD managed to get two of its flagship processors onto one PCB, yielding that crazy-fast halo board. Of course, the most recent example is AMD’s Radeon HD 7990, rated for a scorching 375 W.

With Hawaii, AMD appears to eschew its sweet-spot philosophy with a 6.2-billion transistor GPU that’s 44% more complex than Tahiti, and yet manufactured using the same 28 nm process. A die size of 438 mm² is still quite a bit smaller than Nvidia’s GK110. However, it’s still larger than any graphics processor we’ve seen from the company (including R600 at 420 mm²; Tahiti only occupies 352 mm²).


Radeon R9 290X
Radeon R9 280X
GeForce GTX Titan
GeForce GTX 780
Process
28 nm
28 nm28 nm28 nm
Transistors
6.2 Billion
4.3 Billion
7.1 Billion
7.1 Billion
GPU Clock
1 GHz
1 GHz
836 MHz
863 MHz
Shaders
2816
2048
2688
2304
FP32 Performance
5.6 TFLOPS
4.1 TFLOPS
4.5 TFLOPS
4.0 TFLOPS
Texture Units
176
128
224
192
Texture Fillrate
176 GT/s
128 GT/s
188 GT/s
166 GT/s
ROPs
64
32
48
48
Pixel Fillrate
64 GP/s
32 GP/s
40 GP/s
41 GP/s
Memory Bus
512-bit
384-bit
384-bit
384-bit
Memory
4 GB GDDR5
3 GB GDDR5
6 GB GDDR5
3 GB GDDR5
Memory Data Rate
5 Gb/s
6 Gb/s
6 Gb/s
6 Gb/s
Memory Bandwidth
320 GB/s
288 GB/s
288 GB/s
288 GB/s
Board Power
250 W (Claimed)
250 W
250 W
250 W

Again, the underlying GCN architecture on which Hawaii is based remains similar. The Compute Unit building block looks exactly the same, with 64 IEEE 754-2008-compliant shaders split between four vector units and 16 texture fetch load/store units.

There are a few tweaks to the design though, including device flat addressing to support standard calling conventions, precision improvements to the native LOG and EXP operations, and optimizations to the Masked Quad Sum of Absolute Difference (MQSAD) function, which speeds up algorithms for motion estimation. Incidentally, all of those features debuted alongside the Bonaire GPU we reviewed back in March (AMD Radeon HD 7790 Review: Graphics Core Next At $150); AMD just wasn’t discussing them yet. And with the introduction of DirectX 11.2, both Bonaire and Hawaii add programmable LOD clamping and the ability to tell a shader if a surface is resident—both of which are tier-two features associated with tiled resources.

But the arrangement of AMD’s CUs is different. Whereas Tahiti boasted up to 32 Compute Units, totaling 2048 shaders and 128 texture units, Hawaii wields 44 CUs organized into four of what AMD is calling Shader Engines. The math adds up to 2816 aggregate shaders and 176 texture units. Operating at up to 1 GHz (this becomes an important distinction later), that’s 5.63 TFLOPS of floating-point performance. We've also come to learn that AMD changed the double-precision rate from 1/4 to 1/8 on the R9 290X, yielding a maximum .7 TFLOPS. The FirePro version of this configuration will support full-speed (1/2 rate) DP compute, giving professional users an incentive to spring for Hawaii's professional implementation.

Hawaii also employs eight revamped Asynchronous Compute Engines, responsible for scheduling real-time and background task to the CUs. Each ACE manages up to eight queues, totaling 64, and has access to L2 cache and shared memory. In contrast, Tahiti had two ACEs. The Kabini and Temash APUs we wrote about earlier this year come armed with four. Why is Hawaii so dramatically different? Some evidence exists to suggest that Hawaii’s asynchronous compute approach is heavily influenced by the PlayStation 4’s design, though AMD won't confirm this itself. Apparently, Sony’s engineers are looking forward to lots of compute-heavy effects in next-gen games, and dedicating more resources to arbitrating between compute and graphics allows for efficiencies that weren’t possible before.

Tahiti’s front-end fed vertex data to the shaders through a pair of geometry processors. Though its quad Shader Engine layout, Hawaii doubles that number, facilitating four primitives per clock cycle instead of two. There’s also more interstage storage between the front- and back-end to hide latencies and realize as much of that peak primitive throughput as possible.

In addition to a dedicated geometry engine (and 11 CUs), Shader Engines also have their own rasterizer and four render back-ends capable of 16 pixels per clock. That’s 64 pixels per clock across the GPU—twice what Tahiti could do. Hawaii enables up to 256 depth and stencil operations per cycle, again doubling Tahiti’s 128. On a graphics card designed for high resolutions, a big pixel fill rate comes in handy, and in many cases, AMD claims, this shifts the chip’s performance bottleneck from fill to memory bandwidth.

The shared L2 read/write cache grows from 768 KB in Tahiti to 1 MB, divided into 16 64 KB partitions. This 33% increase yields a corresponding bandwidth increase between the L1 and L2 structures of 33% as well, topping out at 1 TB/s.

It makes sense, then, that increasing geometry throughput, adding 768 shaders, and doubling the back-end’s peak pixel fill would put additional demands on Hawaii’s memory subsystem. AMD addresses this with a redesigned controller. The new GPU features a 512-bit aggregate interface that the company says occupies about 20% less area than Tahiti’s 384-bit design and enables 50% more bandwidth per mm². How is this possible? It actually costs die space to support very fast data rates. So, hitting 6 Gb/s at higher voltage made Tahiti less efficient than Hawaii’s bus, which targets lower frequencies at lower voltage, and can consequently be smaller. Operating at 5 Gb/s in the case of R9 290X, the 512-bit bus pushes up to 320 GB/s using 4 GB of GDDR5. In comparison, Tahiti maxed out at 288 GB/s.

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Top Comments
  • 99 Hide
    BigMack70 , October 23, 2013 10:04 PM
    Thank goodness AMD had some sense with the pricing. Finally, at long last, Nvidia can stop raping consumers' wallets due to lack of competition.

    This is win-win-win for everyone (except maybe Nvidia).

    Hope we never have to deal with a $1000 single GPU fiasco again. Good riddance.
  • 79 Hide
    beta212 , October 23, 2013 9:09 PM
    That's incredible. Especially at high res, I wonder how they do it. But the low price alone is enough to blow the competition away. Seriously think about it, it's around half the price for higher performance!
    - AMD: We're not aiming for the ultra high end.
    I think Nvidia just got trolled.
  • 60 Hide
    anxiousinfusion , October 23, 2013 9:37 PM
    Wait the 290 X... X? is going to be $550?! Forgive me, padre for I have sinned.
Other Comments
  • 79 Hide
    beta212 , October 23, 2013 9:09 PM
    That's incredible. Especially at high res, I wonder how they do it. But the low price alone is enough to blow the competition away. Seriously think about it, it's around half the price for higher performance!
    - AMD: We're not aiming for the ultra high end.
    I think Nvidia just got trolled.
  • 29 Hide
    slomo4sho , October 23, 2013 9:12 PM
    Great price point. This card has already broken world records just a few hours after release!


  • 25 Hide
    aznguy0028 , October 23, 2013 9:19 PM
    I was thinking about hopping on the 7970ghz when it's on sale, but after seeing this, it's time to break apart the piggy bank for the 290x, what value!
  • 33 Hide
    Benthon , October 23, 2013 9:21 PM
    Like the conclusion said, you just can't argue about aesthetics and thermals at this price point/performance. Well done AMD, lets see team green's response! Go consumer!
  • 21 Hide
    tuklap , October 23, 2013 9:25 PM
    This is awesome for us ^_^
  • 23 Hide
    Shankovich , October 23, 2013 9:27 PM
    Wow, and it's pegged at 73% too. Even if nVidia's "780ti" beats the 290X, it probably won't beat a 290X running at full power. And if mantle does make some big performance boosts, nVidia is going to be in a really tight spot. Looking forward to what they'll do. In the mean time, loving this competition! We all win in the end.
  • 13 Hide
    julianbautista87 , October 23, 2013 9:31 PM
    daaaaayyyyyuuuummmm
  • 60 Hide
    anxiousinfusion , October 23, 2013 9:37 PM
    Wait the 290 X... X? is going to be $550?! Forgive me, padre for I have sinned.
  • 21 Hide
    Darkerson , October 23, 2013 9:40 PM
    Good job, AMD!
  • 21 Hide
    jkhoward , October 23, 2013 9:40 PM
    I just purchased this card from Newegg.
  • 15 Hide
    CaptainTom , October 23, 2013 9:41 PM
    Wow AMD. GG! You exceeded every possible expectation! Have fun with your GTX 780 Ti Fanboys!!!!!
  • 19 Hide
    ilysaml , October 23, 2013 9:42 PM
    Time to Upgrade my HD 6950 to 290X, and my 1080P to 2500x Monitor.
  • 37 Hide
    lt_dan_zsu , October 23, 2013 9:44 PM
    I've never been more blown away by a hardware review. Never have I seen a gpu beat another gpu at just over half the cost.
  • 11 Hide
    DarkForce_256 , October 23, 2013 9:45 PM
    So what's the deal with the 290?
  • 9 Hide
    shin0bi272 , October 23, 2013 9:51 PM
    it always tickles the hell out of me when an amd card ties or about ties an nvidia card in one game then in an nvidia physx game the amd kicks the crap out of the nvidia card... Of course if you know why that happens in metro you know its more of a fault of the coders not physx but its still funny.
  • 10 Hide
    jimmysmitty , October 23, 2013 9:58 PM
    $550 is not bad for the fact that it beats the 780 easily and even pressures the Titan.

    Most of the higher resolution gaming wins come from the larger memory bandwidth and of course more vs the 780.

    That's a good sign. Maybe NVidia will drop prices and push this to $400-$450 and I will pick one up when there is a Vapor-X version of course,
  • 2 Hide
    markbro89 , October 23, 2013 9:59 PM
    Where to buy?! Newegg still says coming soon D:
  • -7 Hide
    DarkForce_256 , October 23, 2013 10:03 PM
    So what's the deal with the 290?
  • 99 Hide
    BigMack70 , October 23, 2013 10:04 PM
    Thank goodness AMD had some sense with the pricing. Finally, at long last, Nvidia can stop raping consumers' wallets due to lack of competition.

    This is win-win-win for everyone (except maybe Nvidia).

    Hope we never have to deal with a $1000 single GPU fiasco again. Good riddance.
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