The RV870 Story: AMD Showing up to the Fight
by Anand Lal Shimpi on February 14, 2010 12:00 AM EST- Posted in
- GPUs
TPS Rep...err PRS Documents
At ATI there’s a document called the Product Requirement Specification, PRS for short. It was originally a big text document written in Microsoft Word.
The purpose of the document is to collect all of the features that have to go into the GPU being designed, and try to prioritize them. There are priority 1 features, which are must-haves in the document. Very few of these get canned. Priority 2, priority 3 and priority 4 features follow. The higher the number, the less likely it’ll make it into the final GPU.
When Carrell Killebrew first joined ATI, his boss at the time (Dave Orton) tasked him with changing this document. Orton asked Carrell to put together a PRS that doesn’t let marketing come up with excuses for failure. This document would be a laundry list of everything marketing wants in ATI’s next graphics chip. At the same time, the document wouldn’t let engineering do whatever it wanted to do. It would be a mix of what marketing wants and what engineering can do. Orton wanted this document to be enough of a balance that everyone, whether from marketing or engineering, would feel bought into when it’s done.
Carrell joined in 2003, but how ATI developed the PRS didn’t change until 2005.
The Best Way to Lose a Fight - How R5xx Changed ATI
In the 770 story I talked about how ATI’s R520 delay caused a ripple effect impacting everything in the pipeline, up to and including R600. It was during that same period (2005) that ATI fundamentally changed its design philosophy. ATI became very market schedule driven.
ATI's R520 Architecture. It was delayed.
The market has big bulges and you had better deliver at those bulges. Having product ready for the Q4 holiday season, or lining up with major DirectX or Windows releases, these are important bulges in the market. OEM notebook design cycles are also very important to align your products with. You have to deliver at these bulges. ATI’s Eric Demers (now the CTO of AMD's graphics group) put it best: if you don’t show up to the fight, by default, you lose. ATI was going to stop not showing up to the fight.
ATI’s switch to being more schedule driven meant that feature lists had to be kept under control. Which meant that Carrell had to do an incredible job drafting that PRS.
What resulted was the 80% rule. The items that made it onto the PRS were features that engineering felt had at least an 80% chance of working on time. Everyone was involved in this process. Every single senior engineer, everyone. Marketing and product managers got their opportunities to request what they wanted, but nothing got committed to without some engineer somewhere believing that the feature could most likely make it without slipping schedule.
This changed a lot of things.
First, it massively increased the confidence level of the engineering team. There’s this whole human nature aspect to everything in life, it comes with being human. Lose confidence and execution sucks, but if you are working towards a realistic set of goals then morale and confidence are both high. The side effect is that a passionate engineer will also work to try and beat those goals. Sly little bastards.
The second change is that features are more easily discarded. Having 200 features on one of these PRS documents isn’t unusual. Getting it down to about 80 is what ATI started doing after R5xx.
In the past ATI would always try to accommodate new features and customer requests. But the R5xx changes meant that if a feature was going to push the schedule back, it wasn’t making it in. Recently Intel changed its design policy, stating that any feature that was going into the chip had to increase performance by 2% for every 1% increase in power consumption. ATI’s philosophy stated that any feature going into the chip couldn’t slip schedule. Prior to the R5xx generation ATI wasn’t really doing this well; serious delays within this family changed all of that. It really clamped down on feature creep, something that’s much worse in hardware than in software (bigger chips aren’t fun to debug or pay for).
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Dudler - Sunday, February 14, 2010 - link
Your reasoning is wrong. The 57xx is a performance segment down from the 48xx segment. By your reasoning the 5450 should be quicker than the last gen 4870X2. The 5870 should be compared to the 4870, the 5850 to 4850 and so on.Regarding price, the article sure covers it, the 40nm process was more expensive than TSMC told Amd, and the yield problems factored in too. Can't blame Amd for that can we?
And finally, don't count out that Fermi is absent to the party. Amd can charge higher prices when there is no competition. At the moment, the 5-series has a more or less monopoly in the market. Considering this, I find their prices quite fair. Don't forget nVidia launched their Gtx280 at $637....
JimmiG - Friday, February 19, 2010 - link
"Your reasoning is wrong. The 57xx is a performance segment down from the 48xx segment. "Well I compared the cards across generations based on price both at launch and how the price developed over time. The 5850 and 4850 are not in the same price segment of their respective generation. The 4850 launched at $199, the 5850 at $259 but quickly climbed to $299.
The 5770 launched at $159 and is now at $169, which is about the same as a 1GB 4870, which will perform better in DX9 and DX10. Model numbers are arbitrary and at the very best only useful for comparing cards within the same generation.
The 5k-series provide a lot of things, but certainly not value. This is the generation to skip unless you badly want to be the first to get DX11 or you're running a really old GPU.
just4U - Tuesday, February 16, 2010 - link
and they are still selling the 275,285 etc for a hefty chunk of change. I've often considered purchasing one but the price has never been right and mail in rebates are a "PASS" or "NO THANKS" for many of us rather then a incentive.I haven't seen the mail-ins for AMD products much I hope their reading this and shy away from that sort of sales format. To many of us get the shaft and never recieve our rebates anyway.
BelardA - Monday, February 15, 2010 - link
Also remind people... the current GTX 285 is about $400 and usually slower than the $300 5850. So ATI is NOT riping off people with their new DX11 products. And looking at the die-size drawings, the RV870 is a bit smaller than the GT200... and we all now that FERMI is going to be another HUGE chip.The only disappointment is that the 5750 & 5770 are not faster than the 4850/70 which used to cost about $100~120 when inventory was good. Considering that the 5700 series GPUs are smaller... Hell, even the 4770 is faster than the 5670 and costs less. Hopefully this is just the cost of production.
But I think once the 5670 is down to $80~90 and the 5700s are $100~125 - they will be more popular.
coldpower27 - Monday, February 15, 2010 - link
nVidia made a conscious decision, not to fight the 5800 Series, with the GTX 200 in terms of a price war. Hence why their price remain poor value. They won't win using a large Gt200b die vs the 5800 smaller die.Another note to keep in mind is that the 5700 Series, also have the detriment of being higher in price due to ATi moving the pricing scale backup a bit with the 5800 Series.
I guess a card that draws much less power then the 4800's, and is close to the performance of those cards is a decent win, just not completely amazing.
MonkeyPaw - Sunday, February 14, 2010 - link
Actually, the 4770 series was meant to be a suitable performance replacement for the 3870. By that scheme, the 5770 should have been comperable to the 4870. I think we just hit some diminishing returns from the 128bit GDDR5 bus.nafhan - Sunday, February 14, 2010 - link
It's the shaders not the buswidth. Bandwidth is bandwidth however you accomplish it. The rv8xx shaders are slightly less powerful on one to one basis than the rv7xx shaders are.LtGoonRush - Sunday, February 14, 2010 - link
The point is that an R5770 has 128-bit GDDR5, compared to an R4870's 256-bit GDDR5. Memory clock speeds can't scale to make up the difference from cutting the memory bus in half, so overall the card is slower, even though it has higher compute performance on the GPU. The GPU just isn't getting data from the memory fast enough.Targon - Monday, February 15, 2010 - link
But you still have the issue of the 4870 being the high end from its generation, and trying to compare it to a mid-range card in the current generation. It generally takes more than one generation before the mid range of the new generation is able to beat the high end cards from a previous generation in terms of overall performance.At this point, I think the 5830 is what competes with the 4870, or is it the 4890? In either case, it will take until the 6000 or 7000 series before we see a $100 card able to beat a 4890.
coldpower27 - Monday, February 15, 2010 - link
Yeah we haven't seen ATi/nVidia achieved the current gen mainstream faster then the last gen high end. Bandwidth issues are finally becoming apparent.6600 GT > 5950 Ultra.
7600 GT > 6800 Ultra.
But the 8600 GTS, was only marginally faster then the 7600 GT and nowhere near 7900 GTX, it took the 8800 GTS 640 to beat the 7900 GTX completely, and the 800 GTS 320 beat it, in the large majority of scenarios, due to frame buffer limitation.
The 4770 slots somewhere between the 4830/4850. However, that card was way later then most of the 4000 series. Making it a decent bit faster then the 3870, which made more sense since the jump from 3870 to 4870 was huge, sometimes nearly even 2.5x could be seen nearly, given the right conditions.
4670 was the mainstream variant and it was, most of the performance of the 3800 Series, it doesn't beat it though, more like trades blows or is slower in general.