Can I use SATA3 drive  when my MOBO just supports SATA2? 

Western Digital SATA III Desktop Drives are backwards compatible with SATA II Motherboards if a jumper shunt is set on pins 5 & 6.

Hello – 

Thanks for the info – if  I dont strap the drive ( pin 5 & 6 ) will it still work? 

Unlikely (But not impossible), as most SATA II Motherboards will not recognize SATA III Hard Disk Drives while working on SATA III mode.

its more Likey to work with the jumper off (just its 100% will work if the jumper is used) some older motherboards auto speed negotiation fails to work if that happens use the jumper (the worst that can happen the disk is not detected)

but i would not rush out and replace the motherboard (not untill intel and AMD get native SATA III built in Corectly) as for HDDs SATA III is more an gimmic that looks good to plaster on boxs and sites (more useful for SSDs as they can all ready max SATA III out now)

Ahhh, interesting, might explain why a new Sata3 drive I got displays errors on my sata2 . Will try the jumper pins