Adaptive AA IQ and Performance

Adaptive Anti-Aliasing IQ and Performance

As I already discussed on the architecture detail, ATI is bringing a new type of AA to the X1000 series of cards called Adaptive AA that attempts to correct jagged lines on the interior of textures that would otherwise not be affected by standard AA.  NVIDIA introduced this same feature with their G70 core 7800 series parts.  Let’s have a look at how the ATI and NVIDIA image quality differs in a very common case — prison levels and fences on HL2. 

Half-Life 2 – Prison

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 197

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 198

Full Size

Full Size

Enlarged 200%

Enlarged 200%

Original Image

Original Image

Both the NVIDIA 7800 GTX and the ATI X1800 XT show similar levels of aliasing on the interior of the fence shown. 

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 199

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 200

Full Size

Full Size

Enlarged 200%

Enlarged 200%

Original Image

Original Image

The ATI implementation of Adaptive AA produces a very similar image quality to the NVIDIA Interior AA, as I expected.  Both look MUCH better than the original image with maybe a slight bit less noise going to the NVIDIA 7800 image.

Performance is of course slightly affected by all of this additional sampling being done. 

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 201

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 202

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 203

ATI R520: Radeon X1800, X1600 and X1300 Review - Graphics Cards 204

The first set shows the ‘control’ runs of the prison level where adaptive and interior AA are disabled and the second set shows both cards with their respective modes enabled.  As you can see, both cards see a modest performance deficit; but one that is not very dramatic at least in HL2.

« PreviousNext »