Originally Posted by jyavenard
I am pretty sure that you can't active both video cards at the same time. You must use the hardware switch and perform a reboot
Except that the 'hardware' switch is now some sort of soft-switch when you have an OS that appears to support this functionality (Vista does, Linux presents to the BIOS like it does somehow). And lspci shows us that both cards are presented by the BIOS, and neither LED on the switch are lit (when the switch is active, a LED is lit indicating mode, and one of the graphics cards is entirely hidden from the OS).
I haven't had the time until now, but in the next few days I'm going to try shoe-horning a dumped bios into X at runtime by mmapping it, and pointing Xorg's BiosBase to the mmap pointer... it's an ugly, ugly hack, but I'm so over having to boot XP, then *nix to get decent hardware acceleration...
Would really appreciate some official comment here, since these dynamic hybrid setups are likely to become more common in the near future...