i want to ask u.....so this is my problem
i just bought WDC Caviar Blue - WD5000AAKX and i just realize that storage interface is SATA 6Gb/s ,my motherboard is GA-H61M-DS2(rev 3.0) and only support SATA 3gb/s.....can i use my storage?or i must change motherboard if i want to use it?
sata 3 is 6GB/s, sata 2 is 3GB/s. hdd-s need at most 1-200mb/second (about 2GB/s) it's simply impossible for them to use all the bandwidth offered by a sata 2 interface...
so the answers above are correct, you dont need to change motherboards you can connect to the sata 2 interface without any issues. but the hdd will not work any slower compared to sata 3. it's not the interface slowing it down, it's running at top speed even on sata 2.
the only storage that can be affected by the lower speed of the old sata interface are ssd drives, and not even those feel much of a performance hit as only the top sequential throughput is affected by the limit (2-300MB/sec instead of 500 which is their max) so you would see a difference only in benchmarks.