On Wed, Dec 15, 2010 at 11:35 AM, Grant Edwards <grant.b.edwa...@gmail.com> wrote: > On 2010-12-15, Andrea Conti <a...@alyf.net> wrote: >>> E-SATA != SATA !!!! >> >> Nah. They are *exactly* the same. > > Not according to Wikipedia -- it says the electrical specs for eSATA > are different than the specs for "normal" SATA. I've seen that stated > in other places as well. I don't have copies of the two specs, so I > can't say I'm 100%, but I believe the Wikipedia page. >
It is true, and has to be for cost reasons. 1) Internal SATA drives are at the end of a single cable and don't require hot-plugging logic be built into the SATA port driver on the SATA controller because they are always powered up. (They are inside the case) 2) External SATA drives are at the end of 1) an internal cable, 2) a case SATA-eSATA connector, and 3) an external eSATA cable along with whatever is inside the eSATA case. eSATA compatible ports must include hot-plugging logic. For cost/simplicity reasons chip manufacturers are free to remove hot-plugging logic from any port for which they don't intend eSATA compatibility. The logic and timing of the signals on SATA and eSATA cables is (TTBOMK) intended to be identical. What those signals look like at different places in the cable chain will be different. - Mark
