I915

i915 is a kernel module:

a xorg.conf could look something like this:

Section "Device"

       ### Available Driver options are:-
       ### Values: : integer, <f>: float, <bool>: "True"/"False",
       ### <string>: "String", <freq>: "<f> Hz/kHz/MHz",            
       ### <percent>: "<f>%"                            
       ### [arg]: arg optional
       Option     "DRI"                "true" # [<bool>]
       Option     "ColorKey"                  #      
       Option     "VideoKey"                  # 
       Option     "FallbackDebug"       "false"      # [<bool>]
       Option     "Tiling"             "true"        # [<bool>]
       Option     "LinearFramebuffer"  "true"       # [<bool>]  
       Option     "Shadow"             "false"        # [<bool>]
       Option     "SwapbuffersWait"    "false"        # [<bool>]
       Option     "TripleBuffer"       "false"       # [<bool>] 
       Option     "XvMC"                      # [<bool>]       
       Option     "XvPreferOverlay"           # [<bool>]
       Option     "DebugFlushBatches" "false"         # [<bool>]
       Option     "DebugFlushCaches"   "false"        # [<bool>]
       Option     "DebugWait"          "false"        # [<bool>]
       Option     "HotPlug"            "true"       # [<bool>] 
       Option     "RelaxedFencing"     "false"        # [<bool>]
       Option     "BufferCache"        "true" # [<bool>]        
       Option "Throttle" "false"
       Identifier  "Card0" 
       Driver      "intel"   
       BusID       "PCI:0:2:0"

EndSection More info can be found in intel(9)