Texture borders

Discussion created by BradO on Feb 28, 2010
Latest reply on Mar 16, 2010 by BradO
Bad performance when using texture borders with Raedon x700 or Raedon HD 4200 integrated chip

I'm writing a terrain rendering library that currently uses OpenGL as it's rendering api.  I'm testing it on a Radeon x700 and a Radeon HD 4200 integrated chip.  When I use texture borders(which eliminates some artifacts between adjacent tiles in the map) the chips seem to drop into software rendering mode and it runs at < 1 fps.  Without the border the text program runs at ~150 fps.  I use 32 bit RGBA textures that are mipmaped, and linear interpolation between mip maps.  I use GL_CLAMP_TO_EDGE for texture wrapping.  Is it expected that both these chips don't render well with texture borders?  I'm using the latest version of drivers on the x700, and I'll have to check on the 4200.  If these chips don't handle the texture borders well I can make some changes to account for that, I'm just wondering if it's one of my settings that's causing problems.

Thanks for any help