i just replaced my old 2006 era 3.5 in. wd sata II drive with a 2.5 in. seagate sata II ssd hybrid drive. it has the same sata connectors that the sata II/III ssd drives do, and the same as the old drive. had to get a 2.5->3.5 adapter, got one with a heat sink while i was at it. drive plugs into adapter, and is screwed to the heat sink part, old sata cables plug into adapter. i've heard some ssd's may have trouble with older MBs, so it would depend on your MB model and the ssd. the hybrid works a treat in my old system unjumpered, gives me 500GB and very fast reads as well, tho not near as fast as a true ssd.