ATI Radeon HD 3870 & 3850: A Return to Competition
by Anand Lal Shimpi & Derek Wilson on November 15, 2007 12:00 AM EST- Posted in
- GPUs
2, 3 or 4 GPUs: Introducing CrossFire X
DirectX 9 didn't support more than 3 frame render ahead, and we saw this manifest in less than optimal scaling on NVIDIA's quad SLI solutions. Now that Vista and DirectX 10 are around, it's possible to render 4 or more frames ahead, and quad solutions have a higher potential. AMD is taking advantage of this via CrossFireX which currently enables up to 4 GPUs to be connected in the same system with three CrossFire bridges. It's not a pretty solution: you'll need a non NVIDIA chipset motherboard with 4 physical x16 PCIe slots.
Aside from potential performance scalability, there is also the capability to support up to 8 monitors from one system with 4 graphics cards installed. While this isn't as universally desired, it could be something fun to play with. We don't currently have a platform solution that we can use to test this yet, but we will certainly test this when we are able.
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ChronoReverse - Friday, November 16, 2007 - link
I'll third that. The lines are great. Let's me know the resolution scaling quickly too.peldor - Thursday, November 15, 2007 - link
The line graphs are an improvement over the bar graphs. Good use of colors on these charts too.Anand Lal Shimpi - Thursday, November 15, 2007 - link
I think this is honestly one of the best ideas I've ever heard. If I were talented enough to make a good looking hand puppet...Take care,
Anand
xsilver - Thursday, November 15, 2007 - link
pfft. hand puppets,you need 3d virtual godzilla representing nvidia and 3d virtual king kong representing amd. BTW godzilla would win because it can shoot flames out of its mouth. :P
about the article - is it not feasible that when the price of the 8800gt drops to $220 or lower the 3870 just needs to drop to 85% of that mark? With the 3870 being on the smaller die process, they could afford it or at least try to?
Anand Lal Shimpi - Thursday, November 15, 2007 - link
ohhhhhk, I just said that I'm not talented enough to make a couple of hand puppets, you expect me to be able to create 3D models of reptiles and animate them? I picked text as a medium for my artistic expression for a reason - I'm not exactly artistic otherwise ;)The thought of a $220 8800 GT and a $187 3870 (and thus an even cheaper 3850) is just too much for my mind to handle at this point. I think it'll eventually happen, but not in the near term, these things are too new and both companies like making money.
Take care,
Anand
Anonymous Freak - Thursday, November 15, 2007 - link
Will you do a comparison on CrossFire performance, say, comparing two 3870s to two 8800GTs on X48 vs. 680i? Or even two 3870s on X48 vs. even ONE 8800 Ultra? If 3870 can really sell for $219, or 3850 for less than $200, two of them might well blow away an 8800 Ultra in $/fps terms, even worse than 8800 GT SLI does.Anand Lal Shimpi - Thursday, November 15, 2007 - link
Ask and you shall receive, I just added two new pages to the article - the new Page 10 tackles the CrossFire question.Take care,
Anand
wpapolis - Friday, November 16, 2007 - link
First off, great article! I still surf other web sites but when I read articles produced by Anandtech, they are usually more informative and better presented. Anand, you have a great sense of the relevant information to include in your articles and I do appreciate your effort.Just one small thing regarding CrossFire performance. I was a little disappointed when I read your comment ...
"Scaling looks pretty good from the Radeon HD 3850, however it's still not as good as what NVIDIA is able to achieve with the 8800 GT. NVIDIA consistently achieves about 11% better scaling from one to two GPUs than AMD."
You mentioned that scaling of the 3850's isn't as good as a 8800 GT. In this case, did you compared ...
2 x 3850's with 256MB per card
vs. 2 x 8800 GT's with 512MB per card?
If so, I would be interested in how well ...
2 x 3870's with 512MB per card compares.
I suspect that running a Crossfire configuration sucks up more RAM, so using a 256MB cards doesn't scale as well as using 512MB+ cards.
I know, I know, you didn't get 2 x 3870's, but maybe you can get one more now? Maybe one more page to this article?
Thanks again for your tremendous effort!
Bill
chrispyski - Thursday, November 15, 2007 - link
Nice crossfire chart. I know many people will be thinking about CF'ing the 3850's over a single high-end card (although I totally agree, it does not really work out well in the end)chucky2 - Thursday, November 15, 2007 - link
Those that could have waited for the 3850 and instead bought a 8600 or 2400/2600 are probably kicking themselves right now...Chuck