FYI, I actually managed to shut down the ATI card completely, but without going through the driver. What could interest you is that the ACPI DSDT has methods that seem to set up the two cards (see attached DSDT). Shutting down the radeon is done by calling ATPX(2, [0 0 0]). I did not yet try to find out what the other modes are for. Another interesting bit: when in switchable graphics with Intel as primary the Radeon's SSID is changed from 3d9e to 3d9f, which is used by the DSDT to detect the mode. It could also be used by the radeonhd driver to blacklist the card. lenovo_acpi.tar.bz2 is the quick hack I made to disable the board. Just compile and load the module to kill the board. Note that it will work only if "switchable graphics" is selected in the BIOS. If "discrete graphics" is selected, the DSDT is modified so that ATPX is renamed into XTPX. This works on U330 ... It would be interesting to know if other Lenovo/non-Lenovo laptops with switchable graphics handle it the same way. Sylvain