Supported Cards, RAMDACs, and Bits Per Pixel

Mach64 X Server Release Notes : Supported Cards, RAMDACs, and Bits Per Pixel
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## 1. Supported Cards, RAMDACs, and Bits Per Pixel

The Mach64 X server supports 8bpp with a dot clock up to 80MHz on all Mach64 based cards. On most cards, higher dot clocks and additional depths are available (see the table below). What determines this support is the RAMDAC on your card.

     RAMDAC      Max Dot Clock   BPP   Max Resolution   Video RAM Required
    --------     -------------   ---   --------------   ------------------
    ATI68860         135MHz       8      1280x1024             2Mb
    ATI68860         135MHz      16      1280x1024             4Mb
    ATI68860          80MHz      32       1024x768             4Mb

    ATI68875          80MHz      32       1024x768             4Mb

    CH8398           135MHz       8      1280x1024             2Mb
    CH8398            80MHz      16       1024x768             2Mb
    CH8398            40MHz      32        800x600             2Mb

    STG1702          135MHz       8      1280x1024             2Mb
    STG1702           80MHz      16       1024x768             2Mb
    STG1702           50MHz      32        800x600             2Mb

    STG1703          135MHz       8      1280x1024             2Mb
    STG1703           80MHz      16       1024x768             2Mb
    STG1703           50MHz      32        800x600             2Mb

    AT&T20C408       135MHz       8      1280x1024             2Mb
    AT&T20C408        80MHz      16       1024x768             2Mb
    AT&T20C408        40MHz      32        800x600             2Mb

    3D Rage II (Int) 170MHz       8      1600x1200             4Mb
    3D Rage II (Int) 170MHz      16      1600x1200             4Mb
    3D Rage II (Int) 135MHz      32       1024x768             4Mb

    Internal         135MHz       8      1280x1024             2Mb
    Internal          80MHz      16       1024x768             2Mb
    Internal          40MHz      32        800x600             2Mb

    IBM RGB514       220MHz       8      1600x1200             2Mb
    IBM RGB514       220MHz      16      1600x1200             4Mb
    IBM RGB514       135MHz      32       1024x768             4Mb

    All Others[*]     80MHz       8      1280x1024             2Mb

[*] - The dot clocks are limited to 80MHz and the bpp is limited to 8.

The table above specifies the maximum resolution and the video memory required to run this maximum resolution. Smaller resolutions will require less video memory.

The RAMDAC is reported when you run the Mach64 X server with the "`-probeonly`" command line option. The RAMDAC reported should be correct for all Mach64 cards. It can also be specified in the XF86Config file, but this is not recommended unless the RAMDAC reported in the probeonly output is incorrect. Before specifying the RAMDAC in your XF86Config file visually verify which RAMDAC is on your Mach64 card. If the RAMDAC reported in the probeonly output is definitely different than what you see on the card, then check to see if you have a RAMDAC specified in your XF86Config file. If you do, comment this line out and re-run the Mach64 X server with the "`-probeonly`". If it still reports the incorrect RAMDAC, please send in a bug report to XFree86@XFree86.Org.

The ATI68860 RAMDACs are usually found on ATI Graphics Pro Turbo and ATI WinTurbo cards. The IBM RGB514 RAMDAC is found on the ATI Graphics Pro Turbo 1600 card. The other RAMDACs are usually found on ATI Graphics Xpression, ATI Video Xpression and ATI 3d Xpression cards. Mach64 CT, ET, VT, GT (3D Rage) and 3D Rage II chips have an "Internal" RAMDAC (i.e., it is built into the Mach64 chip).

As advertised, Mach64 graphics cards can use a special 24bpp mode (packed pixel mode), but this is not currently supported in the Mach64 X server. This will be added in a future release.

The Mach64 X server requires the video memory aperture to function properly. This means that ISA Mach64 cards in systems with more than 12Mb of main memory will not work. If you have a PCI based Mach64 card or a VLB based Mach64 card, then the Mach64 X server will work with any amount of main memory.

Accelerated doublescan modes are supported on VT, GT and 3D Rage II based Mach64 cards. Mach64 cards with other chips cannot handle accelerated double scan modes due to a hardware limitation. Non-accelerated doublescan modes should work with the ATI driver in the SVGA X server for all Mach64 cards.

Mach64 X Server Release Notes : Supported Cards, RAMDACs, and Bits Per Pixel
Previous: Mach64 X Server Release Notes
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