I heard it's possible to enable hardware overlay planes on Linux with a Geforce graphics card by adding "CIOverlay" to the graphics section of "XOrg.conf". This would be similar to software emulation that Windows users experience with RivaTuner. I want to test this and if someone has a Quadro 3400/3450 or Quadro 4000 I would appreciate if you can post a copy of your XOrg.conf file. If not the entire file at least the section where your graphics card is listed that includes "CIOverlay". If successful this would basically turn a Geforce 6600 to Quadro 3400, a Geforce 6600 GT to Quadro 3450 and a Geforce 6800 to Quadro 4000 with out hardware modifying the card (relocating resistors).
theres more to quaddro then just the overlay panes but sure.