Re: GTX 470 switching from X to tty freezes system
Well i found out the freezes/lag are only with Compiz enabled and it must be something with the Compiz VSync option. If VSync is disabled X doesn't freeze when Compiz takes over compositing again after switching back from TTY to X. No problems when using Metacity.
Dmesg gives NVRM: Xid errors when the freezes/lag occur. Maybe something with Compiz, Nvidia Driver and GTX400 cards, i put my GTX275 back in and can confirm the issue is gone.