Archived

This topic is now archived and is closed to further replies.

Zantac

hardware question...

Recommended Posts

Zantac    122
Hello! This isn''t as much a problem as it is a question... i''ve been playing around with the mipmap lod bias in d3d, and noticed that changing it had a SEVERE impact on the framerate. In my engine i got double the fps when i went from the smallest lod (cripsiest textures) to the largest lod (blurry textures). Why does it take the hardware (i''ve got a geforce2 mx by the way) longer to render larger textures? Shouldn''t it be all the same since all of the textures are in the card''s local memory? (i haven''t filled it up, so there''s no texture swapping from system memory). Is there anyway to get past the impact on the fillrate (because the game looks much better with crisp textures)? Thanks, Simon

Share this post


Link to post
Share on other sites
Coder10000    122
It takes longer for a graphics card to render larger textures, because they need to access always the complete texture for filtering. Your Geforce 2 MX can''t access the RAM quickly enough to render everything as fast as with the small textures.

Coder10000

Share this post


Link to post
Share on other sites
mhkrause    122
Larger textures take more memory, so it takes longer to swap them into vidmem.

Also, 3d cards have a texel cache. Smaller textures can fit entirely or mostly in the texel cache. Larger textures have more texel cache misses.

Share this post


Link to post
Share on other sites