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 - Thursday, September 24, 2009 - link
Oh really ? Now wait a minute, spin master. When the site here whined about "paper launch" it was Derek who brought up a two or three year old nvidia card, and cried and whined about it. Then speculated the GTX275 was paper, and then "a phantom card".Well, that didn't happen.... no apologies about it ever either.
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The PAPER launches of late are ATI ATI ATI ! ! !
We have the 4770, and now this one !
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Gee, when ATI BLOWS IT, we suddenly talk in vague terms about "the companies" having "papery launches" as " the general rule of thumb of how it's done.." - and that makes us "not a fan boy!??!"
R0FLMAO !!!!
Yes, of course, since the red ati is bleeding paper launches and the last one from nvidia one can actually cite is YEARS AND YEARS ago, yes, of course, you're correct, it's "unnamed companies in the multiple" that "do it"....
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I swear to god, I cannot even believe the massive brainwashing that is a gigantic pall all over the place.
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If I'm WRONG, please be kind, and tell me what nvidia paper launches I missed.... PLEASE LET ME KNOW.
Genx87 - Wednesday, September 23, 2009 - link
Is\was a good idea to shoot for as this is most certainly what Nvidia is going to attempt to achieve. But I am a bit disappointed this care rarely achieved it.I do like angle independent AF though. Should be interesting to see what Nvidia brings to the table. But kind of like the CPU situation(i5) I am kind of meh. But will say this has more potential compared to its predecessor than the i5 series does compared to Core 2 Duo.
SiliconDoc - Wednesday, September 23, 2009 - link
I thought that was just great, those pretty pictures, and then I get to reading. I see the 4890 and SQUARES. I see the GTX285, with CIRCLES and an outer rounded octagon.Then the 5870- and it's "perfectly round" angle independent algorithm, but I still see some distortions.
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So I get to reading and am told "the 4890 and 285 are virtually the same". I guess the wheel was first made square, and rolled as well as when it became round. No chance the reviewer could tell the truth and remark that NVidia has the best, until today.. NOPE can't do that!
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Then, of course, the celebration for the "perfection" of the 5870 and ATI's superb success in the "round" category...
EXCEPT:
We get to the actual implementations and NO PERCIEVED DIFFERENCE IS VISUALLY THERE. It cannot be seen. The article even states they searched in vain for some game to show the difference. LOL
All that extra effort to for pete sakes show that ATI superiority...all WASTED EFFORT, but for red roosters I'm certain it was a very exciting quest, titillating, gee a change to take down big green...
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So bottom line is IT'S A BIG FAT ZERO, even the older, worse ati implementation is apparently "non distinguishable".
It is remarked that NVidia doesn't "officially" support this method in game, and of course, after much red rooster effort, one finds out why.
THERE IS NO DIFFERENCE in visual quality. Another phantom red "win".
Another reason NVidia makes money (why waste it on worthless crap in developement that makes no difference), while ATI does not.
Yeah, that was so cool.
So happy the "mental ideation of perfection in the card for ati fans" was furthered. ROFL
Dante80 - Wednesday, September 23, 2009 - link
A quick question. Why is there no 5850 review available atm?1> Was there a separate NDA for the 2 cards?
2> Were there no sample cards given by AMD to reviewers?
3> Did AMD ask reviewers to postpone said reviews due to market supply problems/glitches?
4> Was this a strategy decision by AMD, for marketing or other reasons?
Ryan Smith - Wednesday, September 23, 2009 - link
AMD only provided us with 2 5870s, the 5850 was not sampled. 5800 series cards are in short supply, even for reviewers.Dante80 - Thursday, September 24, 2009 - link
Thank you for the prompt answer, that was what I was guessing too. Cheers...^^Spoelie - Wednesday, September 23, 2009 - link
To get enough 5870 cards in the channel for a hard launch, they used every possible die.There are probably not enough harvested dies to create the 5850 line just yet. And they're not gonna use fully functional ones that can go in a 5870 when supply for them is tight already.
Once the 5850 is launched, demand for them is up and yields matured, they'll have to use fully functional dies to keep supply up, but now they're building up inventory for a hard launch during the coming weeks.
SiliconDoc - Wednesday, September 23, 2009 - link
Uhh, just a minute there feller. The SOFT or PAPER LAUNCH has already hit, the big LAUNCH DATE is today....Newegg is a big ZERO available... (one Powercolor was there 30 mins ago, the other 3 listed are NOT avaailable, I watched them appear last night).
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So, when Ati has a "hard launch" they get "many weeks after the launch date" to "ramp up production" and "fill the need".
ROFLMAO
I was here when this site and the red roosters whined about Nvidia and appear launches, and I believe it was the GTX275 that was predicted to be PAPER (not very long ago in fact) here, and the article EVEN SPECULATED IT WAS A PHANTOM CARD.
All the red roosters piled on, but.... the card was available on launch, it wasn't a PHANTOM, and all that bs was quickly forgotten and shoved into the memory hole like it never happened...
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Oh, but when it's ATI and not Nvidia, the 4770 can remain almost pure paper near forever, and this one, golly it can be 95% paper and it's just " getting ready for a hard launch" WEEKS BEYONDS the launch date!
ROFLMAO
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No bias here?!? "Where's da' bias?!?!" said the red rooster (to the green goblin)...
Give me a break.
chrnochime - Friday, September 25, 2009 - link
Just because you can't find it in the states doesn't mean it's a fake launch. And fake launch? What are you a 12 year old or something? You're like the nvidia version of snakeoil. Just go play with your nvidia part m'kay ?SiliconDoc - Sunday, September 27, 2009 - link
Well, since you insulted, and mischaracterized, I came across the reminder about the 4870 paper launch.Yes, that's correct, this is how ATI rolls, a big fat lying launch date, a piddle of a few cards, then wait a couple weeks or a month.
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" The cards are fast, but as many pointed out HD 5870 is not faster than Geforce GTX 295, which is something that many have expected. Radeon 5850 will also start selling in October time, but remember, last summer when ATI launched 4870, the card was almost impossible to buy and weeks if not months after, the availability finally improved. "
http://www.fudzilla.com/content/view/15643/1/">http://www.fudzilla.com/content/view/15643/1/
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Like I've kept saying, the bias is so bad... I keep discovering more big fat ati blunderous moves, that are instead ascribed to imaginarily to Nvida.
Thanks for the incorrect whining, anger, and standard PC e-mindless chatroom repeated, non original, heard ten thousand times, brainless insult, it actually helped me.
I learned ATI blew their 4870 launch with paper lies as well.
You're a great help friend.