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
A Quick Refresher on the RV770
As Cypress is a direct evolution of the RV770 design, before we talk about what’s new with Cypress we are going to go over a quick rehash of RV770’s internal workings. As it’s necessary to understand how RV770 was built to understand what Cypress changes, if you’re completely unfamiliar with RV770, please take a look at our expanded discussion of RV770 from last year. For the rest of you, let’s get started.
At the center of the RV770 is the Stream Processing Unit (SPU), a single arithmetic logic unit. The RV770 has 800 of these, and they are packaged together in groups of 5 and are what we call a Streaming Processor (SP). A SP contains a register file, a branch predictor, and the aforementioned 5 SPUs, with the 5th SPU being a more complex unit capable of transcendental functions along with the base functions of an ALU. The SP is the smallest unit that can do individual work; every SPU in an SP must execute the same instruction.
For every 16 SPs, AMD groups them together with texture units, L1 cache, shared memory, and controlling logic. This combined block is what AMD calls a SIMD, and RV770 has 10 of them. These 10 SIMDs form the core computational power of the RV770, and in the chip work with various specialized units such as ROPs, rasterizers, L2 cache, and tesselators to form a complete chip.
To utilize the computational power of the hardware, instruction threads are issued to the SPs. These threads are grouped into wavefronts, where there are 64 threads per wavefront. To maximize the utilization of the GPU, threads need to be organized so that they can feed all 5 SPUs in a SP an instruction every clock cycle. Doing this requires extracting instruction level parallelism (ILP) out of programs being passed to the GPU, which is difficult task of AMD’s compiler.
If SPUs go unused, then the performance of the chip suffers due to underutilization. This design gives AMD a great deal of theoretical computational power, but it is always a challenge to fully exploit it.
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SiliconDoc - Monday, September 28, 2009 - link
When the GTX295 still beats the latest ati card, your wish probably won't come true. Not only that, ati's own 4870x2 just recently here promoted as the best value, is a slap in it's face.It's rather difficult to believe all those crossfire promoting red ravers suddenly getting a different religion...
Then we have the no DX11 released yet, and the big, big problem...
NO 5870'S IN THE CHANNELS, reports are it's runs hot and the drivers are beta problematic.
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So, celebrating a red revolution of market share - is only your smart aleck fantasy for now.
LOL - Awwww...
silverblue - Monday, September 28, 2009 - link
It's nearly as fast as a dual GPU solution. I'd say that was impressive.DirectX 11 comes out in less than a month... hardly a wait. It's not as if the card won't do DX9/10.
Hot card? Designed to be that way. If it was a real issue they'd have made the exhaust larger.
Beta problematic drivers? Most ATI launches seem to go that way. They'll be fixed soon enough.
SiliconDoc - Monday, September 28, 2009 - link
Gee, I thought the red rooster said nvidia sales will be low for a while, and I pointed out why they won't be, and you, well you just couldn'r handle that.I'd say a 60.96% increase in a nex gen gpu is "impressive", and that's what Nvidia did just this last time with GT200.
http://www.anandtech.com/video/showdoc.aspx?i=3334...">http://www.anandtech.com/video/showdoc.aspx?i=3334...
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BTW - the 4870 to 4890 move had an additional 3M core transistors, and we were told by you and yours that was not a "rebrand".
BUT - the G80 move to G92 added 73M core transistors, and you couldn't stop shrieking "rebrand".
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nearly as fast= second best
DX11 in a month = not now and too early
hot card -= IT'S OK JUST CLAIM ATI PLANNED ON IT BEING HOT !ROFL, IT'S OK TO LIE ABOUT IT IN REVIEWS, TOO ! COCKA DOODLE DOOO!
beta drivers = ALL ATI LAUNCHES GO THAT WAY, NOT "MOST"
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Now, you can tell smart aleck this is a paper launch like the 4870, the 4770, and now this 5870 and no 5850, becuase....
"YOU'LL PUT YOUR HEAD IN THE SAND AND SCREAM IN CAPS BECAUSE THAT'S HOW YOU ROLL IN RED ROOSERVILLE ! "
(thanks for the composition Jared, it looks just as good here as when you add it to my posts, for "convenience" of course)
ClownPuncher - Monday, September 28, 2009 - link
It would be awesome if you were to stop posting altogether.SiliconDoc - Monday, September 28, 2009 - link
It would be awesome if this 5870 was 60.96% better than the last ati card, but it isn't.JarredWalton - Monday, September 28, 2009 - link
But the 5870 *is* up to 65% faster than the 4890 in the tested games. If you were to compare the GTX 280 to the 9800 GX2, it also wasn't 60% faster. In fact, 9800 GX2 beat the GTX 280 in four out of seven tested games, tied it in one, and only trailed in two games: Enemy Territory (by 13%) and Oblivion (by 3%), making ETQW the only substantial win for the GT200.So we're biased while you're the beacon of impartiality, I suppose, since you didn't intentionally make a comparison similar to comparing apples with cantaloupes. Comparing ATI's new card to their last dual-GPU solution is the way to go, but NVIDIA gets special treatment and we only compare it with their single GPU solution.
If you want the full numbers:
1) On average, the 5870 is 30% faster than the 4890 at 1680x1050, 35% faster at 1920x1200, and 45% faster at 2560x1600.
2) Note that the margin goes *up* as resolution increases, indicating the major bottleneck is not memory bandwidth at anything but 2560x1600 on the 5870.
3) Based on the old article you linked, GTX 280 was on average 5% slower than 9800X2 and 59% faster than the 9800 GTX - the 9800X2 was 6.4% faster than the GTX 280 in the tested titles.
4) Making the same comparisons, 5870 is only 3.4% faster than the 4870X2 in the tested games and 45% faster than the 4890HD.
Now, the games used for testing are completely different, so we have to throw that out. DoW2 is a huge bonus in favor of the 5870 and it scales relatively poorly with CF, hurting the X2. But you're still trying to paint a picture of the 5870 as a terrible disappointment when in fact we could say it essentially equals what NVIDIA did with the GTX 280.
On average, at 2560x1600, if NVIDIA's GT300 were to come out and be 60% faster than the GTX 285, it will beat ATI's 5870 by about 15%. If it's the same price, it's the clear choice... if you're willing to wait a month or two. That's several "ifs" for what amounts to splitting hairs. There is no current game that won't run well on the HD 5870 at 2560x1600, and I suspect that will hold true of the GT300 as well.
(FWIW, Crysis: Warhead is as bad as it gets, and dropping 4xAA will boost performance by at least 25%. It's an outlier, just like Crysis, since the higher settings are too much for anything but the fastest hardware. "High" settings are more than sufficient.)
SiliconDoc - Tuesday, September 29, 2009 - link
In other words, even with your best fudging and whining about games and all the rest, you can't even bring it with all the lies from the 15-30 percent people are claiming up to 60.96%--
Yes, as I thought.
zshift - Thursday, September 24, 2009 - link
My thoughts exactly ;)I knew the 5870 was gonna be great based on the design philosophy that AMD/ATi had with the 4870, but I never thought I'd see anything this impressive. LESS power, with MORE power! (pun intended), and DOUBLE the speed, at that!
Funny thing is, I was actually considering an Nvidia gpu when I saw how impressive PhysX was on Batman AA. But I think I would rather have near double the frame rates compared to seeing extra paper fluffing around here and there (though the scenes with the scarecrow are downright amazing). I'll just have to wait and see how the GT300 series does, seeing as I can't afford any of this right now (but boy, oh boy, is that upgrade bug itching like it never has before).
SiliconDoc - Thursday, September 24, 2009 - link
Fine, but performance per dollar is on the very low end, often the lowest of all the cards. That's why it was omitted here.http://www.techpowerup.com/reviews/ATI/Radeon_HD_5...">http://www.techpowerup.com/reviews/ATI/Radeon_HD_5...
THE LOWEST overall, or darn near it.
erple2 - Friday, September 25, 2009 - link
So what you're saying then is that everyone should buy the 9500 GT and ignore everything else? If that's the most important thing to you, then clearly, that's what you mean.I think that the performance per dollar metrics that are shown are misleading at best and terrible at worst. It does not take into account that any frame rates significantly above your monitor refresh are for all intents and purposes wasted, and any frame rates significantly below 30 should by heavily weighted negatively. I haven't seen how techpowerup does their "performance per dollar" or how (if at all) they weight the FPS numbers in the dollar category.
SLI/Crossfire has always been a lose-lose in the "performance per dollar" category. Curiously, I don't see any of the nvidia SLI cards listed (other than the 295).
That sounds like biased "reporting" on your part.