AMD's Radeon HD 5870: Bringing About the Next Generation Of GPUs
by Ryan Smith on September 23, 2009 9:00 AM EST- Posted in
- GPUs
DirectCompute, OpenCL, and the Future of CAL
As a journalist, GPGPU stuff is one of the more frustrating things to cover. The concept is great, but the execution makes it difficult to accurately cover, exacerbated by the fact that until now AMD and NVIDIA each had separate APIs. OpenCL and DirectCompute will unify things, but software will be slow to arrive.
As it stands, neither AMD nor NVIDIA have a complete OpenCL implementation that's shipping to end-users for Windows or Linux. NVIDIA has OpenCL working on the 8-series and later on Mac OS X Snow Leopard, and AMD has it working under the same OS for the 4800 series, but for obvious reasons we can’t test a 5870 in a Mac. As such it won’t be until later this year that we see either side get OpenCL up and running under Windows. Both NVIDIA and AMD have development versions that they're letting developers play with, and both have submitted implementations to Khronos, so hopefully we’ll have something soon.
It’s also worth noting that OpenCL is based around DirectX 10 hardware, so even after someone finally ships an implementation we’re likely to see a new version in short order. AMD is already talking about OpenCL 1.1, which would add support for the hardware features that they have from DirectX 11, such as append/consume buffers and atomic operations.
DirectCompute is in comparatively better shape. NVIDIA already supports it on their DX10 hardware, and the beta drivers we’re using for the 5870 support it on the 5000 series. The missing link at this point is AMD’s DX10 hardware; even the beta drivers we’re using don’t support it on the 2000, 3000, or 4000 series. From what we hear the final Catalyst 9.10 drivers will deliver this feature.
Going forward, one specific issue for DirectCompute development will be that there are three levels of DirectCompute, derived from DX10 (4.0), DX10.1 (4.1), and DX11 (5.0) hardware. The higher the version the more advanced the features, with DirectCompute 5.0 in particular being a big jump as it’s the first hardware generation designed with DirectCompute in mind. Among other notable differences, it’s the first version to offer double precision floating point support and atomic operations.
AMD is convinced that developers should and will target DirectCompute 5.0 due to its feature set, but we’re not sold on the idea. To say that there’s a “lot” of DX10 hardware out there is a gross understatement, and all of that hardware is capable of supporting at a minimum DirectCompute 4.0. Certainly DirectCompute 5.0 is the better API to use, but the first developers testing the waters may end up starting with DirectCompute 4.0. Releasing something written in DirectCompute 5.0 right now won’t do developers much good at the moment due to the low quantity of hardware out there that can support it.
With that in mind, there’s not much of a software situation to speak about when it comes to DirectCompute right now. Cyberlink demoed a version of PowerDirector using DirectCompute for rendering effects, but it’s the same story as most DX11 games: later this year. For AMD there isn’t as much of an incentive to push non-game software as fast or as hard as DX11 games, so we’re expecting any non-game software utilizing DirectCompute to be slow to materialize.
Given that DirectCompute is the only common GPGPU API that is currently working on both vendors’ cards, we wanted to try to use it as the basis of a proper GPGPU comparison. We did get something that would accomplish the task, unfortunately it was an NVIDIA tech demo. We have decided to run it anyhow as it’s quite literally the only thing we have right now that uses DirectCompute, but please take an appropriately sized quantity of salt – it’s not really a fair test.
NVIDIA’s ocean demo is a fairly simple proof of concept program that uses DirectCompute to run Fast Fourier transforms directly on the GPU for better performance. The FFTs in turn are used to generate the wave data, forming the wave action seen on screen as part of the ocean. This is a DirectCompute 4.0 program, as it’s intended to run on NVIDIA’s DX10 hardware.
The 5870 has no problem running the program, and in spite of whatever home field advantage that may exist for NVIDIA it easily outperforms the GTX 285. Things get a little more crazy once we start using SLI/Crossfire; the 5870 picks up speed, but the GTX 295 ends up being slower than the GTX 285. As it’s only a tech demo this shouldn’t be dwelt on too much beyond the fact that it’s proof that DirectCompute is indeed working on the 5800 series.
Wrapping things up, one of the last GPGPU projects AMD presented at their press event was a GPU implementation of Bullet Physics, an open source physics simulation library. Although they’ll never admit it, AMD is probably getting tired of being beaten over the head by NVIDIA and PhysX; Bullet Physics is AMD’s proof that they can do physics too. However we don’t expect it to go anywhere given its very low penetration in existing games and the amount of trouble NVIDIA has had in getting developers to use anything besides Havok. Our expectations for GPGPU physics remains the same: the unification will come from a middleware vendor selling a commercial physics package. If it’s not Havok, then it will be someone else.
Finally, while AMD is hitting the ground running for OpenCL and DirectCompute, their older APIs are being left behind as AMD has chosen to focus all future efforts on OpenCL and DirectCompute. Brook+, AMD’s high level language, has been put out to pasture as a Sourceforge project. Compute Abstract Layer (CAL) lives on since it’s what AMD’s OpenCL support is built upon, however it’s not going to see any further public development with the interface frozen at the current 1.4 standard. AMD is discouraging any CAL development in favor of OpenCL, although it’s likely the High Performance Computing (HPC) crowd will continue to use it in conjunction with AMD’s FireStream cards to squeeze every bit of performance out of AMD’s hardware.
Facebook
Twitter
RSS
327 Comments
View All Comments
maomao0000 - Sunday, October 11, 2009 - link
http://www.myyshop.com">http://www.myyshop.comQuality is our Dignity; Service is our Lift.
Myyshop.com commodity is credit guarantee, you can rest assured of purchase, myyshop will
provide service for you all, welcome to myyshop.com
Air Jordan 7 Retro Size 10 Blk/Red Raptor - $34
100% Authentic Brand New in Box DS Air Jordan 7 Retro Raptor colorway
Never Worn, only been tried on the day I bought them back in 2002
$35Firm; no trades
http://www.myyshop.com/productlist.asp?id=s14">http://www.myyshop.com/productlist.asp?id=s14 (Jordan)
http://www.myyshop.com/productlist.asp?id=s29">http://www.myyshop.com/productlist.asp?id=s29 (Nike shox)
shaolin95 - Wednesday, October 7, 2009 - link
So Eyefinity may use 100 monitors but if we are still gaming on the flat plant then it makes no difference to me.Come on ATI, go with the real 3D games already..been waiting since the Radeon 64 SE days for you to get on with it.... :-(
GTX 295 for this boy as it is the only way to real 3D on a 60" DLP.
Nice that they have a fast product at good prices to keep the competition going. If either company goes down we all lose so support them both! :-)
Regards
raptorrage - Tuesday, October 6, 2009 - link
wow what a joke this review is but that i mean the reviewer stance on the 5870 sounds like he is a nvidia fan just because it like what 2-3fps off of the gtx 295 doesn't actually mean it can't catch that gpu as the driver updates come out and get the gpu to actually compete against that gpu and if i remember wasn't the GTX 295 the same when it came out .. its was good but it wasn't where we all thought it should have been then BAM a few months go by and it finds the performance it was missingi don't know if this was a fail on anandtech or the testing practices but i question them as i've read many other review sites and they had a clear view where the 5870 / GTX 295 where neck N neck as i've seen them first hand so i go ahead and state them here head 2 head @ 1920x1200 but at 2560x1600 the dual gpu cards do take the top slot but that is expected but it isn't as big as a margin as i see it.
and clearly he missed the whole point YES the 5870 dose compete with the GTX 295 i just believe your testing practices do come into question here because i've seen many sites where they didn't form the opinion that you have here it seems completely dismissive like AMD has failed i just don't see that in my opinion - I'll just take this review with a gain of salt as its completely meaningless
dieselcat18 - Saturday, October 3, 2009 - link
@Silicon DocNvidia fan-boy, troll, loser....take your gforce cards and go home...we can now all see how terrible ATi is thanks you ...so I really don't understand why people are beating down their doors for the 5800 series, just like people did for the 4800 and 3800 cards. I guess Nvidia fan-boy trolls like you have only one thing left to do and that's complain and cry like the itty-bitty babies that some of you are about the competition that's beating you like a drum.....so you just wait for your 300 series cards to be released (can't wait to see how many of those are available) so you can pay the overpriced premiums that Nvidia will be charging AGAIN !...hahaha...just like all that re-badging BS they pulled with the 9800 and 200 cards...what a joke !.. Oh my, I must say you have me in a mood and the ironic thing is I do like Nvidia as much as ATi, I currently own and use both. I just can't stand fools like you who spout nothing but mindless crap while waving your team flag (my card is better than your's..WhaaWhaaWhaa)...just take yourself along with your worthless opinions and slide back under that slimly rock you came from.
dieselcat18 - Saturday, October 3, 2009 - link
@Silicon DocNvidia fan-boy, troll, loser....take your gforce cards and go home...we can now all see how terrible ATi is thanks you ...so I really don't understand why people are beating down their doors for the 5800 series, just like people did for the 4800 and 3800 cards. I guess Nvidia fan-boy trolls like you have only one thing left to do and that's complain and cry like the itty-bitty babies that some of you are about the competition that's beating you like a drum.....so you just wait for your 300 series cards to be released (can't wait to see how many of those are available) so you can pay the overpriced premiums that Nvidia will be charging AGAIN !...hahaha...just like all that re-badging BS they pulled with the 9800 and 200 cards...what a joke !.. Oh my, I must say you have me in a mood and the ironic thing is I do like Nvidia as much as ATi, I currently own and use both. I just can't stand fools like you who spout nothing but mindless crap while waving your team flag (my card is better than your's..WhaaWhaaWhaa)...just take yourself along with your worthless opinions and slide back under that slimly rock you came from.
Scali - Thursday, October 1, 2009 - link
I have the GPU Computing SDK aswell, and I ran the Ocean test on my 8800GTS320. I got 40 fps, with the card at stock, with 4xAA and 16xAF on. Fullscreen or windowed didn't matter.How can your score be only 47 fps on the GTX285? And why does the screenshot say 157 fps on a GTX280?
157 fps is more along the lines of what I'd expect than 47 fps, given the performance of my 8800GTS.
Ryan Smith - Thursday, October 1, 2009 - link
Full screen, 2560x1600 with everything cranked up. At that resolution, it can be a very rough benchmark.The screenshot you're seeing is just something we took in windowed mode with the resolution turned way down so that we could fit a full-sized screenshot of the program in to our document engine.
Scali - Friday, October 2, 2009 - link
I've just checked the sourcecode and experimented a bit with changing some constants.The CS part always uses a dimension of 512, hardcoded, so not related to the screen size.
So the CS load is constant, the larger you make the window, the less you measure the GPGPU-performance, since it will become graphics-limited.
Technically you should make the window as small as possible to get a decent GPGPU-benchmark, not as large as possible.
Scali - Friday, October 2, 2009 - link
Hum, I wonder what you're measuring though.I'd have to study the code, see if higher resolutions increase only the onscreen polycount, or also the GPGPU-part of generating it.
Scali - Thursday, October 1, 2009 - link
That's 152 fps, not 257, sorry.