Provided by: xserver-xorg-video-s3_0.6.3-4build2_amd64 bug


       s3 - S3 video driver


       Section "Device"
         Identifier "devname"
         Driver "s3"
         [Option "optionname" ["optionvalue"]]


       The s3 driver supports PCI video cards based on the following S3 chips:

       Trio32      86C732

       Trio64      86C764

       Trio64V+    86C765

       Aurora64V+  86CM65

       Trio64UV+   86C767

       Trio64V2/DX 86C775

       Trio64V2/GX 86C785

       Vision964   86C964

       Vision968   86C968

       Also driver supports the following RAMDACs:

       IBM 524, IBM 524A, IBM 526, IBM 526DB

       TI ViewPoint 3025


       s3  is  an  Xorg  driver  for  S3  based video cards. The driver provides full accelerated
       support for the following colour depths: 8, 15, 16 and  24.  The  overlay  video  (Xv)  is
       supported  in  depths  16  and 24 for the Trio64V+, Trio64UV+, Trio64V2/DX and Trio64V2/GX


       Please refer to xorg.conf(5) for general configuration details.  This section only  covers
       configuration  details specific to this driver. All options names are case and white space
       insensitive when parsed by the server, for  example,  "trio  32/64"  and  "Trio32/64"  are

   Chip overriding
       The  driver  auto-detects  the  chipset  and  RAMDAC,  but the following Chipset names may
       optionally be specified in the configuration file "Device" section, and will override  the

           "964-0", "964-1"  86C964 (rev.0 and rev.1)

           "968"             86C968

           "Trio32/64"       86C732/86C764

           "Aurora64V+"      86CM65

           "Trio64UV+"       86C767

           "Trio64V2/DX/GX"  86C775/86C785

       The 86C765 (Trio64V+) is Chipset "Trio32/64" with ChipRev greater or equal 0x40.

       An overriding of RAMDAC auto-detection currently is not implemented.

   Colour depth
       For  every supported colour depth the X server automatically selects an appropriate number
       of bits per pixel (bpp) for framebuffer. The depth 8 is represented by 8  bpp  framebuffer
       (1  byte/pixel),  the  depths  15  and 16 (respectively 5.5.5 and 5.6.5 pixel formats) are
       represented by  the  16  bpp  framebuffer  (2  bytes/pixel).  Whenever  the  depth  24  is
       configured,  the  X server by default uses the 32 bpp framebuffer (4 bytes/pixel), and the
       hardware is adjusted accordingly to the X.8.8.8 pixel format, where X is the ignored upper

       As  the  second  option  for  the  depth  24, the X server can be configured to use 24 bpp
       framebuffer with the 8.8.8 pixel format (3 bytes/pixel), which is supported  by  Trio64V+,
       Trio64UV+,  Trio64V2/DX  and  Trio64V2/GX. If the video board has limited video RAM the 24
       bpp framebuffer has an advantage over 32 bpp framebuffer as it  requires  less  memory  to
       store screen, and, therefore, more space will be available for a video frame (see "Overlay
       video" section).  The 24 bpp framebuffer can be selected by X server's option -fbbpp 24 or
       by specifying DefaultFbBpp option in xorg.conf(5):

           Section "Screen"
             DefaultFbBpp 24
             DefaultDepth 24

       However, the 24 bpp framebuffer mode has the hardware limitations: (i) the 2D acceleration
       doesn't work with this mode (use the "shadowFB" option to speed  up  drawing  routines  in
       this  case);  (ii)  24 bpp framebuffer cannot be used with either interlaced or doublescan
       graphics modes.

   Overlay video
       If your video board has limited RAM it would be useful to estimate how large  video  frame
       might  be  placed in offscreen video memory. Suppose that the video board has 2 MB of RAM,
       and X server is configured to display 800x600 with the depth 24. By  default  the  32  bpp
       framebuffer will be chosen for this depth, so 800 x 600 x 4 = 1875 kB will be reserved for
       screen, and 2 MB - 1875 kB = 173 kB will remain for the offscreen area. This is sufficient
       space,  for  example,  for the VCD NTSC 352x240 frame. If you need to upscale video with a
       bigger frame, but it doesn't fit the offscreen area, the only way to do this is  to  lower
       either  the  resolution  or framebuffer's depth or both before the viewing, otherwise, you
       will get the allocation error and will not  see  the  video.  For  example,  with  24  bpp
       framebuffer and the same resolution 800x600 the offscreen area will be about 640 kB - it's
       enough for the 640x480 frame. 800x600 with the 16 bpp framebuffer gives about 1110  kB  of
       offscreen  area  -  this  allows  to  upscale  up  to 768x576 movies. Note, that all movie
       resolutions in examples above are provided  as  a  reference;  the  movies  can  have  the
       different  aspect  ratios  and  non-standard  dimensions. A total pixel amount is the main
       consideration not the certain width and height.

       Due to hardware limitation the overlay video will not work with the  interlaced/doublescan
       modes. Downscaling is not implemented in hardware.

   Configuration options
       The following display Options are supported:

       Option "HWCursor" "boolean"
              Enable   or  disable  the  hardware  cursor.  Currently,  hardware  cursor  is  not
              implemented, so the option will be ignored. Default: off (software cursor).

       Option "NoAccel" "boolean"
              Disable acceleration. Very useful for determining if the driver has  problems  with
              drawing  and  acceleration routines. This is the first option to try if your server
              runs but you see graphic corruption on the screen. Using it decreases  performance,
              as  it  uses  software  emulation  for  drawing  operations  the  video  driver can
              accelerate with hardware. Default: off (acceleration is enabled).

       Option "ShadowFB" "boolean"
              Use shadow framebuffer. Disables hardware acceleration. Use this  option  when  the
              hardware acceleration is not available or undesirable. Default: off.

       Option "XVideo" "boolean"
              Enable or disable Xv support. Default: on.

       The following video memory Options are supported:

       Option "slow_dram_refresh" "boolean"
              Enable three refresh cycles per scanline. Default: off (one refresh cycle).

       Option "slow_edodram" "boolean"
              Switch  to 2-cycle EDO mode. Try this if you encounter pixel corruption. Using this
              option will cause a decrease in performance. Default: off (BIOS defaults).

       Option "slow_dram" "boolean"
              For Trio and Aurora64V+ chips: increase -RAS Precharge Timing to 3.5 MCLK. Try this
              option if you encounter pixel errors. Default: off (BIOS defaults).

       Option "slow_vram" "boolean"
              For  Vision964, Vision968 chips: increase -RAS Low Timing to 4.5 MCLK. Default: off
              (BIOS defaults).


       Xorg(1), xorg.conf(5), Xserver(1), X(7)


       Thomas Roell, Mark Vojkovich, Kevin E. Martin, Amancio Hasty, Jon N. Tombs and others were
       the original authors of driver for XFree86 3.x. Ani Joshi reworked driver for XFree86 4.x.
       The further modifications were made by the  following  contributors:  Adam  Jackson,  Alan
       Coopersmith,  Dave  Airlie,  Andrew  Radrianasulu,  Paulo  Cesar  Pereira de Andrade, Eric
       Anholt, Søren Sandmann Pedersen, Alex Deucher, Evgeny M. Zubok, Daniel Stone and others.

       The manual was written by Evgeny M. Zubok <>