Introduction

Over the past several months, we’ve detailed the performance of ATI’s latest Radeon X1K cards at length. Back in October we took our first look at the Radeon X1800 family, previewing the performance of the X1800 XT and XL cards, the Radeon X1800 XT 512MB in particular turned into an impressive performer in subsequent driver updates from ATI. Then, at the beginning of this year we took a look at ATI’s Super AA anti-aliasing modes.

In that article we found that ATI’s Radeon X1800 XT was able to scale to very high AA modes with a surprisingly small performance hit thanks to ATI’s revamped compositing engine introduced in the Radeon X1800 CrossFire card. 8xAA was practically free, while the X1800 CrossFire setup was delivering pretty good performance at high resolutions even once 14xAA was enabled. This continued to be the case for the Radeon X1900 CrossFire as well.

But the one topic we hadn’t discussed at length (that you continued to remind us about in the comments) is ATI’s unique ability to support anti-aliasing with high dynamic range lighting (HDR), a feature found on all of their X1K cards. Only ATI’s Radeon X1K cards are capable of pulling off this feat.

Oblivion HDR Off

Oblivion HDR On

Oblivion HDR Off

Oblivion HDR On

It’s important to note that when we refer to HDR+AA we’re talking about games that utilize floating-point values to generate their HDR lighting effects, these games include titles such as Far Cry, Splinter Cell: Chaos Theory, and Oblivion. Valve managed to integrate HDR support into their Half-Life 2 engine, but this utilizes your graphics card’s pixel shaders to produce HDR. This is why older graphics cards that technically didn’t support HDR can still run these effects in Half-Life 2 and HL2 Lost Coast.

By combining AA with HDR gamers can still get the razor sharp edges provided by MSAA with the environmental effects of HDR. Tomorrow’s games (including Epic’s upcoming shooter Unreal Tournament 2007) will increasingly take advantage of HDR lighting, so ATI fans have made the argument that this is one area where ATI’s Radeon X1K cards are more future-proof than NVIDIA’s GeForce 7. Up to this point however the argument has been tough to prove, as most online reviews have skipped over the topic.

Far Cry HDR Off

Far Cry HDR On

Far Cry HDR Off

Far Cry HDR On

You see, HDR lighting comes with a significant performance hit even with today’s fastest graphics cards. As a result, most reviewers and end users have just assumed that combining one performance-sapping feature (HDR) with another (AA) would result in sluggish frame rates. As we’re about to show you today however, apparently that isn’t the case, as ATI’s latest X1K cards are capable of delivering very good frame rates in games like Oblivion and Far Cry, even once the game’s eye candy settings are cranked up and HDR+AA is enabled!