Radeon X.Org 7.4.0 Driver Brings More Tiling, R300/R500 GLAMOR
Phoronix: Radeon X.Org 7.4.0 Driver Brings More Tiling, R300/R500 GLAMOR
A stable update to the xf86-video-ati "Radeon" X.Org driver was released on Wednesday...
Does R600 have tiling enabled by default?
AFAIR R300/R500 has a dedicated 2D engine. Won't the switch to Glamor slow down things?
I would request some benchmarks on this.
glamor is not enabled by default for any asics other than SI and newer. The changes mentioned for r3xx-r5xx just allow you to force glamor on via xorg.conf option for users that want to play with it.
Doesn't radeon default to EXA (running on the 3D engine) for 3xx-5xx these days anyways ?
Originally Posted by Mat2
My recollection was that XAA used the 2D engine quite a bit but EXA did not...
It's not that the 2D engine is faster or that XAA or EXA accelerates more stuff. 2D and 3D engines have different capabilities. 2D engines can can basically do 3 things:
1. blit (move rectangles from one place to another)
2. fill (draw a filled rectangle)
2D engines can't do coordinate transforms (scaling or rotation), alpha-blending, etc. so those operations require the 3D engine.
Core X and render were deisgned prior to GPU acceleration so a lot of ops map really poorly to modern hardware. Even today, pure software rendering is still faster than hw in many cases.
XAA only attempted to accelerate core X rendering. Additionally offscreen image support broken probably 6 or 7 years ago, so XAA only accelerated on screen images which means that for the most part, XAA almost always uses software rendering. Additionally, XAA was generally only exposed on older asics that had limited 3D engines, no support for tiled buffers, etc. Software fallbacks were relatively cheap on those cards for onscreen stuff and all offscreen buffers were rendered with software to begin with.
EXA took the most commonly used core X operations (blits and fills) and added limited support for also accelerating render (coordinate transforms, alpha blending, etc.).
For EXA, we use the 2D engine for blits and fills if the hw has it. For everything else, we use the 3D engine.
glamor accelerates core X and render using OpenGL.