The RV870 Story: AMD Showing up to the Fight
by Anand Lal Shimpi on February 14, 2010 12:00 AM EST- Posted in
- GPUs
What Made it All Ok: 4 GPUs in < 6 Months
Through a lot of hard work and sacrifice, even on Carrell’s part, ATI cut the RV870 from as much as 22mm on a side down to roughly 18mm x 18mm. The problem is that RV770 was around 16mm on a side. The RV870 was still too big.
Carrell wanted to cut it down even more, but two things changed his mind. First, in order to build 870 in the space of a 770 ATI would have to cut out much more from the chip than Carrell originally tought. One of the things that would have to go was some of the shader core.
In order to run the GDDR5 memory at the sort of data rates that ATI was targeting for the 5870 the analog PHYs on the chip had to grow considerably. At 16mm on a side ATI would either have to scale back memory bandwidth or eat into the shader core area. Either way we would’ve had a slower chip.
I asked Carrell if 16mm on a side would’ve made the RV870 $100 cheaper at launch, putting it on par with the RV770 launch prices. He said no. I didn’t find out why until much later, but I’ll save that story for another time.
Sacrificing performance to meet the 16mm x 16mm die size targets wasn’t going to happen, but what ultimately convinced Carrell to go with a larger die this time around was something that ATI didn’t get nearly enough praise for: the ability to launch 4 different 40nm DirectX 11 GPUs in less than 6 months.
Remember that Carrell’s beef with building the biggest GPU possible is that it takes too long for the majority of customers to get access to derivatives of that GPU. Look at how long it took G80 or GT200 to scale down. And who knows when we’ll see $150 Fermi/GF100 derivatives.
But ATI Engineering promised two things. First, that Cypress would have a successor called Juniper that would be ready around the same time. Secondly, two more GPUs would follow and the whole stack will be done and out in less than 6 months. ATI came close in 2008 with 3 GPUs in 3 months, but the fourth member of the 4000 series didn’t show up until April of 2009.
It wasn’t an impossible feat. ATI does have concurrent design teams and a lot of engineering resources in India/China. By working on Juniper in tandem with Cypress, assuming there were no show stopping bugs, ATI could exploit efficiencies in two teams effectively working on the same hardware (Juniper was just half a Cypress).
The idea of taking such a huge risk made Carrell uncomfortable. Running two GPU designs in parallel, for the same family of chips, is risky. If everything works out perfectly, you get two chips out at the same time. If it doesn’t, you’ve just tied up two design teams on one product generation. A slip here would give ATI its own Fermi.
What ultimately sold Carrell was the fact that engineering told him that they believed they could pull it off. Carrell believes in people. He believes if you expect the best out of those around you, then that’s what you’ll get. He couldn’t reconcile his beliefs with doubting the schedule engineering was feeding him. Carrell nervously signed off and the Evergreen stack was born.
Cypress and Juniper were delivered nearly at the same time. In fact, Juniper was ready a bit earlier and was sampled to developers months before ATI launched the 5000 series. Cedar and Redwood followed, not to mention a dual-Cypress board that became the Radeon HD 5970. And all of this was done and ready in less than 6 months (the chips themselves were all ready within 4 months).
When the smoke cleared ATI had new DirectX 11 parts at $600, $400, $300, $200, $150, $100 and $60. The Windows 7/DirectX 11 market bulge just got serviced.
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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.