Messages in this thread | | | Subject | Re: [Linux-fbdev-devel] Re: FBdev updates. | From | Antonino Daplas <> | Date | 21 Feb 2003 06:00:53 +0800 |
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On Fri, 2003-02-21 at 03:58, James Simmons wrote: > > > I was for five weeks in U.S., so I did not do anything with > > matroxfb during that time. I plan to use fillrect and copyrect > > from generic code > > I have ported the accelerated functions to the new api. What is left is to > deal with the loadfont and putcs issue which I'm working on the code right > now. > > > (although it means unnecessary multiply on > > generic side, and division in matroxfb, > > ???? > > > but well, if we gave > > up on reasonable speed for fbdev long ago...). > > This is not true. Several benchmarks have shown a large performance > improvement in 2.5.X. >
2.5.x might be a bit slower with bpp8 but at higher color depths is significantly faster. And this is done with a single generic color exapnd function that replaces the entire fbcon-cfb*.c in 2.4. And it will theoretically still draw correctly whatever the condition is (any bpp from 1-32, unaligned origin, pitch, width, etc).
Drivers with accelerated color expansion, if done correctly, _should_ perform better whatever the color depth.
However, using fonts with widths not divisible by 8 will be several folds slower. This should be helped if we add some form of tile/texture blitting support to fbdev.
Note: I cannot test with 12x22 fonts in 2.4 because some/most drivers do not support it.
Tony
no accel scrollmode: yredraw font: 8x16 visual: packed pixels
time cat /usr/src/linux/MAINTAINERS
linux-2.4.20
bpp8 ---- real 0m2.499s user 0m0.000s sys 0m2.500s
bpp16 ----- real 0m8.324s user 0m0.000s sys 0m8.320s
bpp24 ----- real 0m12.364s user 0m0.000s sys 0m12.370s
bpp32 ----- real 0m16.274s user 0m0.000s sys 0m16.280s
linux-2.5.62
bpp8 ---- real 0m2.557s user 0m0.003s sys 0m2.553s
bpp16 ----- real 0m4.051s user 0m0.002s sys 0m4.050s
bpp24 ----- real 0m9.520s user 0m0.000s sys 0m9.520s
bpp32 ----- real 0m7.496s user 0m0.002s sys 0m7.494s
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