The RV870 Story: AMD Showing up to the Fight
by Anand Lal Shimpi on February 14, 2010 12:00 AM EST- Posted in
- GPUs
Adjusting Trajectory & Slipping Schedule
Carrell didn’t believe in building big chips anymore. It wasn’t that it was too difficult, it’s that it took too long for a $600 GPU to turn into a $200 GPU. AMD believed that the most important market was the larger (both in quantity and revenue) performance mainstream segment.
Rather than making the $200 - $300 market wait for new technology, Carrell wanted to deliver it there first and then scale up/down to later address more expensive/cheaper markets.
The risk in RV770 was architecture and memory technology. The risk in RV870 was architecture and manufacturing process, the latter which was completely out of AMD’s control.
Early on Carrell believed that TSMC’s 40nm wasn’t mature enough and that when it was ready, its cost was going to be much higher than expected. While he didn’t elaborate on this at the time, Carrell told me that there was a lot of information tuning that made TSMC’s 40nm look cheaper than it ended up being. I'll touch on this more later on in the article.
Carrell reluctantly went along with the desire to build a 400+ mm2 RV870 because he believed that when engineering wakes up and realizes that this isn’t going to be cheap, they’d be having another discussion.
In early 2008, going into Februrary, TSMC started dropping hints that ATI might not want to be so aggressive on what they think 40nm is going to cost. ATI’s costs might have been, at the time, a little optimistic.
Engineering came back and said that RV870 was going to be pretty expensive and suggested looking at the configuration a second time.
Which is exactly what they did.
The team met and stuck with Rick Bergman’s compromise: the GPU had to be at least 2x RV770, but the die size had to come down. ATI changed the configuration for Cypress (high end, single GPU RV870) in March of 2008.
And here’s where the new ATI really showed itself. We had a company that had decided to both 1) not let schedule slip, and 2) stop designing the biggest GPU possible. Yet in order to preserve the second belief, it had to sacrifice the first.
You have to understand, changing a chip configuration that late in the game, 1.5 years before launch, screws everything up. By the time RV770 came out, 870 was set in stone. Any changes even a year prior to that resets a lot of clocks. You have to go back and redo floorplan and configuration, there’s a lot of adjusting that happens. It takes at least a couple of weeks, sometimes a couple of months. It impacted schedule. And ATI had to work extremely hard to minimize that where possible. The Radeon HD 5870 was around 30 - 45 days late because of this change.
Remember ATI’s nothing-messes-with-schedule policy? It took a lot of guts on the part of the engineering team and Rick Bergman to accept a month+ hit on redesigning RV870. If you don’t show up to the fight, you lose by default, and that’s exactly what ATI was risking by agreeing to a redesign of Cypress.
This is also super important to understand, because it implies that at some point, NVIDIA made a conscious decision to be late with Fermi. ATI wasn’t the only one to know when DX11/Windows 7 were coming. NVIDIA was well aware and prioritized features that delayed Fermi rather than align with this market bulge. GPUs don’t get delayed without forewarning. AMD risked being late in order to make a smaller chip, NVIDIA risked being late to make a bigger one. These two companies are diverging.
The actual RV870
Engineering was scrambling. RV870 had to be a lot smaller yet still deliver 2x the computational power of RV770. Features had to go.
Facebook
Twitter
RSS
132 Comments
View All Comments
papapapapapapapababy - Sunday, February 14, 2010 - link
Ok, ok, great read, but i have to hate a bit, 1,2,3 GO! hey Carrell here is my top priority feature for your next PRS1 -Drivers that dont suck ass-
"The performance was still a problem and the RV740 was mostly lost as a product" ...
the fuk? the 4770 is the BEST card i ever had, PERIOD. cheap, fast, cool, the perfect RV770, thanks !
bla bla Carrell "He’s single handedly responsible for getting Eyefinity included in the Evergreen stack"
Meh? who gives a sht. , Carrell give me console like gpu scaling, so we can finally play crysis at 1080p, another one for that PRS
"Carrell went to David Glenn, head of software engineering at ATI and asked"
drivers that dont suck, please?
" There were also game compatibility concerns that made ATI not interested in the software approach"
Lol i wonder why? i think i know why. Hardware, hardware, what about the software,Carrell?
ok, thats it. not much to complain this time, flawless job ati guys
f0d - Sunday, February 14, 2010 - link
long time reader/first time postingive never felt the need to post anything but with this article i really wanted to say:
"thank you"
the insights we get in these articles is amazing (i also read the first when it was done)
i like the "no technical or maketing bs" writing of this story and all the little pieces of information like with the eyefinity story and sideport
please do as much of these type of stories as possible - it must be difficult to talk to the right people and get the right information out of them and also be allowed to publish it but it makes a great read
Robert Kooijman - Sunday, February 14, 2010 - link
Awesome article Anand!Also specially created an account to inform you how impressed I am with articles like these. A real treat these behind the scenes stories in non-marketing language. Keep 'm coming, compliments!
- Friday, February 19, 2010 - link
bravowhen do the (tech industry) book's come out??
Kryten - Sunday, February 14, 2010 - link
Informative, interesting, inspirational, edifying and very well written. Here's hoping for more research and articles like this.greenguy - Sunday, February 14, 2010 - link
Hi Anand, I've been reading your stuff for 3 years or so, I just created an account to tell you how awesome that article was. Very nice work. This sort of content is why I read Anandtech. (My other favorite articles have been the SSD articles and the i5-750 article.)I especially like to hear about AMD/ATI - I like having a serious competitor to Intel out there, and I commend AMD for opening up their graphics card documentation. I hope that they continue to fund the Linux driver development (both open and closed source). I also hope their CPU division can put the heat on Intel again, especially on the low power front.
at80eighty - Sunday, February 14, 2010 - link
Anand I was just telling someone yesterday how I wish you guys got more popularity for the different approach you guys havebetween articles like this and the new beta Bench tab - I think I'm really looking forward to your proposed changes you promised this year
insurgent - Sunday, February 14, 2010 - link
I had a really great time reading the article, thanks!Markstar - Sunday, February 14, 2010 - link
Also a big thank you from me for this wonderful article.It's exactly these kind of stories that I hope to find here every morning when I start the day.
JimmiG - Sunday, February 14, 2010 - link
Well the late changes would explain why the RV870 isn't "perfect" like the 770 was. At every price point except at the high-end, it delivers more features, but less or similar performance as the previous generation. For example the 5770 is slower than the 4870, the 5750 is about the same speed and price as the 4850 and so on. Also at the high-end it's more expensive than the 4800-series ever were - the 4870 was only $299 at launch, the 5870 is still at least $399. By this month in 2009, the 4870 was down to $249!