jmke

Updated; read our in-house XP vs Vista AA Scaling article here

In this in-depth article we take a look at the performance of the NVIDIA Geforce GTX 280 and ATI Radeon HD 4870 X2 when anti-aliasing is enabled. We test 8 different games at several different AA levels under Windows XP as well as under Windows Vista. How does performance scale when you go from XP to Vista, how much impact does enabling AA have? Read on to find out!

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Reading through the tons of reviews published yesterday we compared our findings with those from other sites.

While most games showed similar performance differences between the HD4870X2 and GTX 280 we were puzzled by the widely different Crysis results. Some sites reported excellent performance at high resolution with AA enabled for the HD4870X2, while others had it trailing the GTX 280 even without AA.

Digging deeper we started comparing driver versions... but that didn't really clear things up. Then we noticed the Operating System used. Those sites who used Vista SP1 for their benches had the HD4870X2 in the lead, while those running Windows XP SP2/3 had a different outcome. We started comparing all the different test configurations and ended up with only 3 sites which did DX9 vs DX10 comparison and used AA vs noAA and of those three only 1 confirmed that they actually used Windows XP for the DX9 tests and Windows Vista for the DX10 tests. PCINpact Matbe did DX9 vs DX10 path test under Vista, HardwareZone did XP vs Vista test. Worthy to note is though that detail settings under Windows XP were "High" and under Vista set to "Very High".

These were the findings of HardwareZone, using Windows XP vs Windows Vista in Crysis, without AA and with 4xAA enabled:


Going from WinXP DX9 "High" to WinVista DX10 "Very High" at 1920x1200 4xAA causes a massive ~3% performance drop with the ATI HD4870X2... in other words.. under Vista you get higher quality out of the box with DX10 at the same performance as WinXP at "High" Detail... impressive to say the least! The Geforce GTX 280 doesn't fare as well, a ~47% performance drop!

Looking at noAA vs AA numbers we can see that under XP for both GTX 280 and HD4870X2 there is a very noticeable performance drop; but under Vista you almost get free 4xAA with the HD4870X2 as the decrease is quite small.

The results from Matbe reflect these findings, although AA scaling under Vista takes a larger toll here; I'm not sure if they used Windows XP for their DX9 tests, I suspect they are only using the DX9 render path, but still running under Vista.


So if you're a Crysis fan, you might actually be better of with Windows Vista and DX10 VHQ to get free Anti-Aliasing with the ATI HD4870X2!

Attached Thumbnails

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The Senile Doctor

and a 9800gx2, how would it fare against a hd4870x2?

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OC-2-the-death
Where the Reverend is doing his Magick, all mortals be silent
Doom over the world

jmke

Anybody got a spare that they can miss for a weekend?

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The Senile Doctor

just got one
it's a tad far to come and get it uh, and leave me vga-less

__________________
OC-2-the-death
Where the Reverend is doing his Magick, all mortals be silent
Doom over the world

jmke

come and get it: no time
but I can send you replacement VGA

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jmke

some interesting results from tests with HD 4870 X2 here, when running under Vista using DX9 path Crysis runs faster than under XP DX9. Both using "high" gfx preset. (~20% boost!)

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