SATA III SSD on a SATA II Mobo?

[blacknblue2002]

Hi, new to the forum and did a quick search so please don't flame me too hard if this has been asked, but here it goes...

...I'm currently designing a very intense I/O system based on Com Express module form factor. My design deadlines are closing in on me, and I can't wait for the latest/greatest quad core boards to come out, but I really need the bandwidth (throughput) of SATA III for my HD read/write speeds. So here comes the question...

...With the latest SATA III drives about to come to the market, everyone is advertising speeds of 500MB/s and higher write speeds. At this point, using a SATA III SSD is going to bottleneck on the SATA II controller side of the motherboard. My question is, what is the bottleneck speed? Does anybody have actual numbers for this? I've obviously never seen a SATA II drive perform to the full bandwidth of SATA II controllers, and I'm just curious if a SATA III drive would? I know that all of the SATA III drives are supposed to be backwards compatible but was curious if anyone has done this test.

my goal is to RAID.0 two SSD's together and achieve a minimal of 500MB/s...and hopefully a 1TB of storage capacity if the SATA III competitors will hurry and start releasing the 500GB drives.

Thanks for any insight

 

[Indigo]

SATA 2 has a max theoretical bandwidth of 3.0 Gbps or 384 MB/sec. You can use SATA 3 drives on SATA 2 because they maintain backwards compatibility, much like PCI Express 2 does for 1.x and so on.

Without SATA 3 on the board, you're unlikely to reach 500MB/sec since the cap on SATA 2 is lower. You might saturate what the bus is capable of, but since it's point to point, you won't see much slowdown.