High Image Quality Performances

4x FSAA vs 6x FSAA


On element that characterised X1800 when we initially tested it was the performance drop between 4x and 6x FSAA was quite low, something that ATI's engineering stated that had spent some time optimising so that these higher quality setting could be used more of the time. Here we'll check to see if this still hold true on the latest drivers and the X1900 XTX.

Splinter Cell - 4xFSAA vs 6xFSAA

  307200  480000  786432  1310720  1920000 
X1900 XTX - 4x  41.1  61.3  87.4  109.6  122.3 
X1900 XTX - 6x  40.8  59.6  83.3  102.5  113.9 
X1800 XT - 4x  39.2  55.1  69.9  81.8  88.3 
X1800 XT - 6x  39.3  55  70  81.8  88.3 

pixels x fps - Mpixels per second

Difference between 4x and 6x

  640x480  800x600  1024x768  1280x1024  1600x1200 
X1900 XTX  -0.80%  -2.80%  -4.70%  -6.50%  -6.90% 
X1800 XT  0.30%  -0.10%  0.0%  0.0%  0.0% 

percentage

With just differenct levels of FSAA enabled the performance difference between 4x and 6x FSAA on the X1800 is nothing, probably due to the the X1800 being quite shader bound in this title, much of the time. The X1900, on the other hand, does drop in performance a little, to the tune of about 7% at high resolution, but that's still a fairly negligible performance drop for an extra two samples per pixel.

Doom 3 - 4xFSAA vs 6xFSAA

  307200  480000  786432  1310720  1920000 
X1900 XTX - 4x  45.5  71.3  109  142.6  162.4 
X1900 XTX - 6x  46.2  67.9  93.8  113.9  126.5 
X1800 XT - 4x  45.1  69.3  101.8  128.3  140.4 
X1800 XT - 6x  45.4  64.9  86.5  103.5  111.2 

pixels x fps - Mpixels per second

Difference between 4x and 6x

  640x480  800x600  1024x768  1280x1024  1600x1200 
X1900 XTX  1.60%  -4.80%  -13.90%  -20.10%  -22.10% 
X1800 XT  0.70%  -6.40%  -15.10%  -19.30%  -20.80% 

percentage

The performance difference between 4x and 6x FSAA under Doom 3 is a little greater, with a hit a little over 20% in both cases. In this instance we wonder if its a case of the OpenGL drivers not being as tuned as the Direct3D drivers.