View Full Version : Color array with VBO causes 60% slowdown on ATI drivers

08-03-2007, 07:01 PM
On an ATI X1550 (crappy test card, I also have a GEForce 8800) simply adding a color array with a VBO causes a 60% drop in framerate. If I use a regular color array, along with all the other data in VBO's, performance is the same as when no color is used.

08-03-2007, 08:40 PM
Use GLfloat instead of GLubyte... Sound strange but it worked for me...

08-04-2007, 03:00 AM
What type and number of components did you use for the color? ATI cards require 32bit alignment of the stream elements so 3 component UNSIGNED_BYTE element is not supported and the driver needs to emulate that which is slow with the VBO. You need to use 4 component UNSIGNED_BYTE.

08-04-2007, 08:52 AM
I was using just RGB. I switched it to a 4-component color and it ran fine. Thanks for the advice.