The AMD Radeon R9 290X Review
by Ryan Smith on October 24, 2013 12:01 AM EST- Posted in
- GPUs
- AMD
- Radeon
- Hawaii
- Radeon 200
A Bit More On Graphics Core Next 1.1
With the launch of Hawaii, AMD is finally opening up a bit more on what Graphics Core Next 1.1 entails. No, they still aren’t giving us an official name – most references to GCN 1.1 are noting that 290X (Hawaii) and 260X (Bonaire) are part of the same IP pool – but now that AMD is in a position where they have their new flagship out they’re at least willing to discuss the official feature set.
So what does it mean to be Graphics Core Next 1.1? As it turns out, the leaked “AMD Sea Islands Instruction Set Architecture” from February appears to be spot on. Naming issues with Sea Islands aside, everything AMD has discussed as being new architecture features in Hawaii (and therefore also in Bonaire) previously showed up in that document.
As such the bulk of the changes that come with GCN 1.1 are compute oriented, and clearly are intended to play into AMD’s plans for HSA by adding features that are especially useful for the style of heterogeneous computing AMD is shooting for.
The biggest change here is support for flat (generic) addressing support, which will be critical to enabling effective use of pointers within a heterogeneous compute context. Coupled with that is a subtle change to how the ACEs (compute queues) work, allowing GPUs to have more ACEs and more queues in each ACE, versus the hard limit of 2 we’ve seen in Southern Islands. The number of ACEs is not fixed – Hawaii has 8 while Bonaire only has 2 – but it means it can be scaled up for higher-end GPUs, console APUs, etc. Finally GCN 1.1 also introduces some new instructions, including a Masked Quad Sum of Absolute Differences (MQSAD) and some FP64 floor/ceiling/truncation vector functions.
Along with these architectural changes, there are a couple of other hardware features that at this time we feel are best lumped under the GCN 1.1 banner when talking about PC GPUs, as GCN 1.1 parts were the first parts to introduce this features and every GCN 1.1 part (at least thus) far has that feature. AMD’s TrueAudio would be a prime example of this, as both Hawaii and Bonaire have integrated TrueAudio hardware, with AMD setting clear expectations that we should also see TrueAudio on future GPUs and future APUs.
AMD’s Crossfire XDMA engine is another feature that is best lumped under the GCN 1.1 banner. We’ll get to the full details of its operation in a bit, but the important part is that it’s a hardware level change (specifically an addition to their display controller functionality) that’s once again present in Hawaii and Bonaire, although only Hawaii is making full use of it at this time.
Finally we’d also roll AMD’s power management changes into the general GCN 1.1 family, again for the basic reasons listed above. AMD’s new Serial VID interface (SIV2), necessary for the large number of power states Hawaii and Bonaire support and the fast switching between them, is something that only shows up starting with GCN 1.1. AMD has implemented power management a bit differently in each product from an end user perspective – Bonaire parts have the states but lack the fine grained throttling controls that Hawaii introduces – but the underlying hardware is identical.
With that in mind, that’s a short but essential summary of what’s new with GCN 1.1. As we noted way back when Bonaire launched as the 7790, the underlying architecture isn’t going through any massive changes, and as such the differences are of primarily of interest to programmers more than end users. But they are distinct differences that will play an important role as AMD gears up to launch HSA next year. Consequently what limited fracturing there is between GCN 1.0 and GCN 1.1 is primarily due to the ancillary features, which unlike the core architectural changes are going to be of importance to end users. The addition of XDMA, TrueAudio, and improved power management (SIV2) are all small features on their own, but they are features that make GCN 1.1 a more capable, more reliable, and more feature-filled design than GCN 1.0.
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AtwaterFS - Thursday, October 24, 2013 - link
Nice, Nvidia has two choices, drop prices substantially, or drop trou.I certainly hope its the former, as I have no interest in seeing Jen-Hsun's pig in a blanket...
Wreckage - Thursday, October 24, 2013 - link
Not really the Titan slayer we were hoping for.After all this wait and hype it's not surpassing last years GK110. I guess we don't look for big gains in new chips anymore.
The Von Matrices - Thursday, October 24, 2013 - link
This is on the same process node as Titan. Big advances don't happen without process node shrinks, regardless of manufacturer.ninjaquick - Thursday, October 24, 2013 - link
A million times this... GCN is superior to Kepler, and probably Maxwell as well. It doesn't waste tons of die-space on large cache/special decoders/legacy bullshit. Game creators want massive arrays of simple math units that can voraciously crunch numbers, and that is what GCN delivers.EJS1980 - Thursday, October 24, 2013 - link
"GCN is superior to Kepler, and probably Maxwell as well"...HEHEH..... THIS IS PRETTY FUNNY, MAN......THANKS.....I NEEDED THAT! :PWill Robinson - Thursday, October 24, 2013 - link
Yeah right Wreckage...only slayed Titan by about $500 LOLIdiot.
chizow - Thursday, October 24, 2013 - link
Great price and performance from AMD without a doubt, it's not quite a clean sweep but it is certainly a convincing victory for R9 290X, especially at higher resolutions. 780Ti may come close or even exceed 290X, but the damage to Nvidia's product stack has been done.The symmetrical irony here is that this generation's price escalation that began at $550 with AMD's first 28nm part, Tahiti, has come full circle and brought back to balance with AMD's last 28nm part, Hawaii, again at that $550 price point.
I'm happy to see some balance back in the GPU market though, I stated this month's ago at 690 and Titan launch, that this $1K pricing model was an unsustainable business strategy for Nvidia. Now it's going to bite them squarely in the ass. They'll now reap what they sow and have to deal with the angst and anger from all of their most loyal fans who will undoubtedly feel as if they were cheated by the 690, Titan and even 780.
chizow - Thursday, October 24, 2013 - link
I guess it couldn't be all good news though, it looks like the leaked thermals, power consumption and acoustics weren't exaggerated. Definitely loud and hot, with high operating temps. I guess AMD really pushed the GPU to the max, I doubt there will be much more OC headroom, at least with the reference cooler.If Nvidia wasn't so greedy with 690/Titan/780 pricing 290X might've been the next Fermi with mixed reactions, but I'm sure the price and performance will overshadow heat/power concerns.
t41nt3d - Thursday, October 24, 2013 - link
NVIDIA won't be bitten in the ass at all due to the prices of the 690s and Titan. A god awful amount of people have paid $1000 (Including me) for one or more of these cards, and it's taken /8 Months/ for AMD to release a card that goes back and forth with the Titan - Doesn't outright beat it in some games, can go either way.NVIDIA have made a crapload of money from their two overpriced cards and have been reaping off this for a long time now, all they need to do is lower prices and no money lost. It's AMD who's been letting them get away with those prices for so long.
It seems a perfectly viable business strategy for them to have done what they've done and to be so successful at it.
chizow - Thursday, October 24, 2013 - link
I guess we will see, their job just got that much harder to try to sustain this $1000 pricing model now that a $550 card now matches and sometimes outperforms their $1000 card. What kind of performance do you think they're going to need next time to try and justify a $1000 pricetag?Again, Nvidia went down the path of an unsustainable business model predicated on the fact they would be an entire ASIC ahead of AMD. That lead was clearly short-lived due to Kepler's excellent overall performance, but Hawaii brought that dream back down to reality. Sure a bit late, but still in time to crash Nvidia's $1K parade.