XFree do not support DRI acceleration on multiple graphic cards, the only way to use accelrated XFree is to use Nvidia's closed source driver and GLlibrary or a single card using DRI and multiple cards useing Nvidia's closed source drivers. XFree extensions not dependand on DRI should work.
Most of the multiheaded graphic cards can be used only for a single user/display. In order to start independant X servers the heads have to be explicit addressable (which can not be done with most of the cards). It should be possible to use cards with explicit addressable heads for independent displays, but this is not yet tested.
In the following cases it might be possible to use a single multiheaded card for mupliple independant displays :
The card(s) have different PCI Bus ID's for the different heads
(for example Matrox MMS G200/G450)
The card(s) register frame buffer device for each head (only with the linux-2.5/2.6 patch)
Have in mind that the XFree frame buffer driver does not support acceleration and most of the XFree extentions.
(for example Matrox G400DH, G450DH, G550DH)
Using/configuring independent devices for the independent screens/users is pretty hard or not explored, exceptions are the input devices, graphic cards and sound thanks artsd. Some examples of such unexplored areas:
External storage device (USB/Firewire harddisks, CD/DVD drives, ZIP/Floppy drives, memmory stics, ....
USB/Firewire printers, scanners, cameras ...
In case you succeed in configuring such devices for independent usage by multiple users, please share with us how you did it.
![]() | This doesn't mean that the devices wont work, but that every user will have access to all devices. |