ATI Radeon HD 4870 X2 - R700 Preview: AMD's Fastest Single Card

http://www.anandtech.com/video/showdoc.aspx?i=3354&p=7

http://images.anandtech.com/graphs/r...3626/17190.png

http://images.anandtech.com/reviews/.../R700/GRID.jpg




Here we see at 2560x1600, where all of our multi-GPU solutions
struggled to get through the menus and into the game, our 4870 X2
shows a performance increase that illustrates good scaling. We aren't
sure why multi-card CrossFire tanked so much, especially when the 4870
X2 doesn't suffer the same fate. While we don't know all the ins and
outs of the R700 hardware, it may be possible that the hardware offers
tangible advantages over AMD's previous method of performing
CrossFire.

Of course, these are prerelease drivers and we can't say with
certainty that this sort of effect will remain when the hardware is
released. We don't want to stake the farm on this one game test, but
it certainly is quite intreguing. It really is possible that AMD may
have delivered a part that greatly improves upon their previous multi-
GPU solution in a fundamental way. And possibilities are certainly fun
to contemplate.

Beyond that, we do note that in addition to our other added game, GRID
shows a clear advantage over GT200 for AMD's latest generation.

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http://www.anandtech.com/video/showdoc.aspx?i=3354&p=9

Final Words

The two new additions to the test suite, Age of Conan and Race Driver
GRID certainly beef up the portfolio of advantages AMD has in the
current generation. Not only that, but we got quite an interesting
surprise with GRID. Yes, even with R700 the menu screens were slow,
jerky and painful at 2560x1600. But gameplay showed amazing advantages
over RV770 in crossfire. We will still see the upper limit at twice
the performance of a single RV770, but the fact that R700 looks to
offer at least the potential for much better scaling than two card
solutions is a major unknown quantity that could significantly improve
the value of R700 over competing single and multi-card solutions.

But as we've said many times before, the success of CrossFire is in
the consistency of it's performance. We absolutely need to see AMD put
everything they have into making all games past, present, and future
scale well with CrossFire. There needs to not be even the inkling of a
question that CrossFire might not improve the performance of a game.
Until then it is very risky for AMD to put all of its hope for the
high end business into a multi-GPU solution.

Maybe they've done it. Maybe their driver team, by the time 4870 X2
launches will have improved driver support to where it needs to be.
Maybe the changes to the R700 hardware will be enough to fill in the
gaps and bring performance up closer to the theoretical limit for many
more games. The information we have here (especially GRID at high res)
shows the incredible potential R700 has, but it will be absolutely
necessary to wait until launch day to see if the execution behind the
hardware has been enough to realize this potential across the board.

This isn't a case where the quality of the hardware, but rather the
quality of the driver and programming style of modern game developers
will be key in delivering value. For the launch of this card we will
be looking at as large a cross section of games as we can, as the
importance of broad testing has never been more clear than with AMD's
first part after their declared strategy of using single card multi-
GPU solutions to compete in the high end space. We will need to see
more examples of improved single card multi-GPU performance over
CrossFire, as well as improvements in CrossFire performance in general
if AMD is to be taken seriously going forward in the high end space.

The 4870 X2 will be AMD's proving ground. This preview shows what
might be, what could be ... but we must wait for final hardware and
final drivers before we can honestly evaluate the card for what it is.
Let us hope AMD knows how important having pervasive compatibility
really is for this launch.