The RV870 Story: AMD Showing up to the Fight
by Anand Lal Shimpi on February 14, 2010 12:00 AM EST- Posted in
- GPUs
Carrell Loses His Baby: Say Goodbye to Sideport
Sitting at dinner with Eric Demers and Carrell Killebrew is honestly one of the best experiences I’ve ever had working with ATI. Before he got huge and subsequently left, I used to have annual dinners with Pat Gelsinger at Intel. They were amazing. To get to sit at the same table as someone as talented and passionate as a Gelsinger, Demers or Killebrew is one of the most fortunate and cherished parts of my job.
Eric was telling me about how they trimmed down 870 from over 400mm2 down to 334mm2 and how wonderful the end product was. I stopped him and asked for more detail here. I wanted an example of a feature that they had to throw out but they really wanted to keep in. Manufacturers rarely tell you what they threw out, marketing likes to focus on what’s in the chip and make everything sound like a well calculated move. Thankfully, marketing wasn’t allowed to speak at my dinner.
Eric turned to Carrell and said: “i know one feature we could talk about.”
“Sideport”.
Carrell responded, “OH MY GOD, that’s totally not fair.” (note that Carrell does not sound like a teenage girl, imagine that phrase just spoken more engineer-y).
When ATI first talked about the Radeon HD 4870 X2 they told us about a feature called Sideport. It was a port off each RV770 GPU that could be used for GPU-to-GPU communication.
Sideport as it was intended to be used
The whole point of doing CrossFire in alternate frame rendering mode (AFR) is that the chips never have to talk. The minute you have to start synchronizing them, you kill performance. Sideport was supposed to alleviate that.
Unfortunately, due to power reasons, Sideport was never used on the 4870 X2. ATI’s reference design had it disabled and all vendors followed suit.
Sideport was Carrell Killebrew’s favorite feature, and he had to give it up.
In early 2008 ATI realized they had to cut this chip down from 20 - 22mm on a side to 18mm, everyone had to give up something. Carrell was the big advocate for making 870 smaller, he couldn’t be a hypocrite and not give anything up.
A bunch of my conversation with Carrell at this point had to go off the record. Sideport would have been useful in RV870, but it’s unfortunately not there. Although he did tell me not to be surprised if I saw Sideport again at some point. Carrell doesn’t give up easily.
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Spoelie - Thursday, February 18, 2010 - link
phoronix.comfor all things ATi + Linux
SeanHollister - Monday, February 15, 2010 - link
Fantastic work, Anand. It's so difficult to make pieces like this work without coming across as puffery, but everything here feels genuine and evenhanded. Here's hoping for similar articles featuring individuals at NVIDIA, Intel and beyond in the not-too-distant future.boslink - Monday, February 15, 2010 - link
Just like many others i'm also reading/visiting anandtech for years but this article made me register just to say damn good job.Also for the long time i didn't read article from cover to cover. Usually i read first page and maybe second (enough to guess what's in other pages) and than skip to conclusions.
But this article remind us that Graphic card/chip is not only silicon. Real people story is what makes this article great.
Thanks Anand
AmdInside - Monday, February 15, 2010 - link
Great article as usual. Sunspot seems like the biggest non-factor in the 5x00 series. Except for hardware reviews sites which have lots of monitors lying around, I just don't see a need for it. It is like NVIDIA's 3D Vision. Concept sounds good but in general practice, it is not very realistic that a user will use it. Just another check box that a company can point to to an OEM and say we have it and they don't. NVIDIA has had Eyefinity for a while (SLI Mosaic). It just is very expensive since it is targeted towards businesses and not consumers and offers some features Eyefinity doesn't offer.I think NVIDIA just didn't believe consumers really wanted it but added it afterwards just so that ATI doesn't have a checkbox they can brag about. But NVIDIA probably still believes this is mainly a business feature.It is always interesting to learn how businesses make product decisions internally. I always hate reading interviews of PR people. I learn zero. Talk to engineers if you really want to learn something.
BelardA - Tuesday, February 16, 2010 - link
I think the point of Eyefinity is that its more hardware based and natural... not requiring so much work from the game publisher. A way of having higher screen details over a span of monitors.A few games will actually span 2 or 3 monitors. Or some will use the 2nd display as a control panel. With Eyefinity, it tells the game "I have #### x #### pixels" and auto divides the signal onto 3 or 6 screens and be playable. That is quite cool.
But as you say, its a bit of a non-factor. Most users will still only have one display to work with. Hmmm. there was a monitor that was almost seamless 3-monitors built together, where is that?
Also, I think the TOP-SECRET aspect of Sun-Spots was a way of testing security. Eyefinity isn't a major thing... but the hiding of it was.
While employees do move about in the business, the sharing of trade-secrets could still get them in trouble - if caught. It does happen, but how much?
gomakeit - Monday, February 15, 2010 - link
I love these insightful articles! This is why Anandtech is one of my favorite tech sites ever!Smell This - Monday, February 15, 2010 - link
Probably could have done without the snide reference to the CPU division at the end of the article - it added nothing and was a detraction from the overall piece.It also implies a symbiotic relationship between AMDs 40+ year battle with Chipzilla and the GPU Wars with nV. Not really an accurate correlation. The CPU division has their own headaches.
It is appropriate to note, however, that both divisions must bring their 'A' Game to the table with the upcoming convergence on-die of the CPU-GPU.
mrwilton - Monday, February 15, 2010 - link
Thank you, Anand, for this great and fun-to-read article. It really has been some time where I have read an article cover to cover.Keep up the excellent work.
Best wishes, wt
Ananke - Monday, February 15, 2010 - link
I have 5850, it is a great card. However, what people saying about PC gaming is true - gaming on PC slowly fades towards consoles. You cannot justify several thousand-dollar PC versus a 2-300 multimedia console.So powerful GPU is a supercomputer by itself. Please ATI, make better Avivo transcoder, push open software development using Steam further. We need many applications, not just Photoshop and Cyberlink. We need hundreds, and many free, to utilize this calculation power. Then, it will make sense to use this cards.
erple2 - Tuesday, February 16, 2010 - link
Perhaps. However, this "PC Gaming is being killed off by the 2-300 multimedia console" war has been going on since the Playstation 1 came out. PC gaming is still doing very well.I think that there will always be some sort of market (even if only 10% - that's significant enough to make companies take notice) for PC Gaming. While I still have to use the PC for something, I'll continue to use it for gaming, as well.
Reading the article, I find it poignant that the focus is on //execution// rather than //ideas//. It reminds me of a blog written by Jeff Atwood (http://www.codinghorror.com/blog/2010/01/cultivate...">http://www.codinghorror.com/blog/2010/01/cultivate... if you're interested) about the exact same thing. Focus on what you //do//. Execution (ie "what do we have an 80%+ chance of getting done on time) is more important than the idea (ie features you can claim on a spec sheet).
As a hardware developer (goes the same for any software developer), your job is to release the product. That means following a schedule. That means focusing on what you can do, not on what you want to do. It sounds to me like ATI has been following that paradigm, which is why they seem to be doing so well these days.
What's particularly encouraging about the story written was that Management had the foresight to actually listen to the technical side when coming up with the schedules and requirements. That, in and of itself, is something that a significant number of companies just don't do well.
It's nice to hear from the internal wing of the company from time to time, and not just the glossy presentation of hardware releases.
I for one thoroughly enjoyed the read. I liked the perspective that the RV5-- err Evergreen gave on the process of developing hardware. What works, and what doesn't.
Great article. Goes down in my book with the SSD and RV770 articles as some of the best IT reads I've done.