Performance differences

I did some measurements to get a feeling how fast things are on playstation.

The scene contained 2014/1007 textured (mipmaped 64x64x8 to 8x8x8) gradated/goraud shaded Triangles/Quads, drawn with different resolutions (with 2^10 slots for Z-sorting).

values are times in hsync, which GPU (GsDrawOt) needs to draw, and GTE (GsSortObject...) needs to calculate.

what you can see:

Triangles need 60% more time to calculate than Quads

goraud textured quads need 17% more time to calculate than gradated quads
goraud textured quads need 3% more time to draw than gradated quads

512x256 needs 8% more time to draw than 320x256
640x256 needs 3% more time to draw than 512x256

conclusion:

use Quads whenever you can
on scenes where lightning doesn't change (static) precalculate shading and use gradated polygons
there is not that much performance-loss compared with the resolution-profit

640x256x16	quads		triangles (*2)
640x256x16	gradated	goraud	gradated
GPU	234 (1)	240	224
GTE	126	148	205

512x256x16	quads		triangles (*2)
512x256x16	gradated	goraud	gradated
GPU	227 (1)	234	216
GTE	126	148	205

320x256x16	quads		triangles (*2)
320x256x16	gradated	goraud	gradated
GPU	210	219	210(?)
GTE	127	149	210

(1) due to the nonplanar-quad method, Quads need 5 % more time to draw than Triangles, otherwise it should be equal

Andreas Schrattenecker