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    SubjectRe: [Linux-fbdev-devel] Re: FBdev updates.
    From
    Date
    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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