ATI Radeon HD 4870 X2 released and reviewed

Tuesday 12th August 2008, 07:19:00 PM, written by Rys

Multi-GPU has come a long way since NVIDIA resurrected the idea with SLI and NV40 back in the day.  Today's implementations get significant driver engineer hours spent on them, and the form factor has evolved to where two-GPU boards are expected parts of the product stack.

AMD take things a step further these days with multi-GPU that works with multiple active displays while the GPUs are contributing to rendering together, so their solution is instantly more attactive.

Then when you consider the recent release of the excellent Radeon HD 4870, where the underlying GPU has incredible perf/area and perf/watt characteristics, and gobs of raw compute, an X2 was always going to get gamers dribbling.

Tech Report have spent time with product in the weeks following the sanctioned previews, and their analysis highlights a couple of important points.  First is that the new Radeon HD 4870 X2 is the fastest single board graphics product ever engineered.  Fact.

The current state of play means that it's now rare for a popular game not to be supported by at least two GPUs in tandem.  And if support isn't there at game release time, you usually don't have to wait long.

Second is that there are still caveats to observe if you're seriously considering investing in multi-GPU that scales past two chips.  Indeed, it seems like that's still a worthless endeavour for all but the most dedicated.  Tech Report's analysis show that 3- and 4-way GPU setup are a perf/watt disaster for the most part, with limited scaling (although the CPU is the limit in a couple of tests, not the graphics hardware) for a large monetary and environmental cost.

Still, with the Radeon driver letting you be flexible with multi-GPU -- an important point for me personally -- one board seems more than enough.

2.4Tflops of compute, 1GiB of memory per GPU and board physicals that aren't too scary mean that if you have $549 to spend, which is less than the cost of two HD 4870s pretty much, you know what to spend it on.

Check out Tech Report's full analysis.

Discuss on the forums

Tagging

ati ± radeon, x2, rv770, hd, 4870, tech, report, scott, is, teh, funny


Latest Thread Comments (364 total)
Posted by Dooby on Saturday, 06-Sep-08 23:21:35 UTC
Still, without comparing different cards, and only difference OS's, thats a nice article for the next time someone whinges that Vista is slower for games.

Every test shows Vista equal or better than XP, on a £500 system too. Not bad at all.

Posted by pjbliverpool on Sunday, 07-Sep-08 11:50:55 UTC
8xMSAA scaling on the X2 is truly incredible! In Vista you only lose 15% performance on average from going to 0x to 8x MSAA! And thats including Crysis in the average which scales much worse than the other games. Most of those games showed virtually no performance disadvantage when going from 4x to 8x. :grin: And yeah, this article clearly shows Vista as the superior OS for gaming, especially if you have an X2.

Posted by ShaidarHaran on Sunday, 07-Sep-08 14:43:56 UTC
Quoting pjbliverpool
8xMSAA scaling on the X2 is truly incredible!

In Vista you only lose 15% performance on average from going to 0x to 8x MSAA! And thats including Crysis in the average which scales much worse than the other games. Most of those games showed virtually no performance disadvantage when going from 4x to 8x. :grin:
Freakin sweat.

Quoting pjbliverpool
And yeah, this article clearly shows Vista as the superior OS for gaming, especially if you have an X2.
LIES! dirty lies! it tries to takes our precious XP from usssss

Posted by ShaidarHaran on Sunday, 07-Sep-08 14:55:10 UTC
Look at that AA scaling! Jeez ATi... Why aren't they pushing this? Oh, that's right, because up until now, Vista has SUCKED! But it just got a whole lot better, if you're playing on an X2 at least ;)

Stalker fer cryin out loud! 52 fps in XP - 99 fps in Vista - grr, nevermind. CFX didn't work under XP. why even include the numbers then?

cripes! FREE 16x AA in Crysis of all games?

too bad the engine scales so poorly that the fastest dual-gpu video card of our times with some of the best AA performance known to man can't pull off even 30 fps @ VHQ 1920x1200

Posted by Dooby on Thursday, 11-Sep-08 16:13:53 UTC
Disabling CAT AI turns off CF on the X2 (ie, makes it a "single" 4870) and i get 49fps in CoD4.

Image: http://www.pogdesign.co.uk/stuff/cod4single.jpg

Enabling it, turns on the CF and i get 129fps

Image: http://www.pogdesign.co.uk/stuff/cod4dual.jpg

137% increase, from 100% more gpus. Niiiiiice.

Settings are 2560x1600, eveything Max'd, 4xAA (in game) 16xAF.

Posted by AnarchX on Thursday, 11-Sep-08 16:36:00 UTC
Do not forget that AI is bundled with game and filter optimizations.
So you did not only disable CF.

Posted by Silent_Buddha on Friday, 12-Sep-08 04:49:14 UTC
And AI also fixes bugs in rendering with affected games which could potentially slow a game down drastically if AI is turned off.

Regards,
SB

Posted by Raqia on Tuesday, 30-Sep-08 00:41:43 UTC
Quick question and sorry if it's been asked before:

What accounts for the difference in performance between crossfire and the x2 cards?

Posted by Kaotik on Tuesday, 30-Sep-08 03:07:12 UTC
Quoting Raqia
Quick question and sorry if it's been asked before:

What accounts for the difference in performance between crossfire and the x2 cards?
The bridgechip on X2 and in 512MB vs 1GB (per chip) memory in most cases, I believe

Posted by Raqia on Tuesday, 30-Sep-08 03:13:46 UTC
Quoting Kaotik
The bridgechip on X2 and in 512MB vs 1GB (per chip) memory in most cases, I believe
How much more bandwidth does the bridge-chip provide than crossfire? Is it also better latency?


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