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On Wednesday 15 December 2010 11:58:13 Mark Knecht wrote: |
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> On Wed, Dec 15, 2010 at 11:35 AM, Grant Edwards |
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> |
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> <grant.b.edwards@×××××.com> wrote: |
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> > On 2010-12-15, Andrea Conti <alyf@××××.net> wrote: |
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> >>> E-SATA != SATA !!!! |
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> >> |
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> >> Nah. They are *exactly* the same. |
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> > |
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> > Not according to Wikipedia -- it says the electrical specs for eSATA |
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> > are different than the specs for "normal" SATA. I've seen that stated |
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> > in other places as well. I don't have copies of the two specs, so I |
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> > can't say I'm 100%, but I believe the Wikipedia page. |
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> |
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> It is true, and has to be for cost reasons. |
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> |
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> 1) Internal SATA drives are at the end of a single cable and don't |
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> require hot-plugging logic be built into the SATA port driver on the |
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> SATA controller because they are always powered up. (They are inside |
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> the case) |
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> |
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> 2) External SATA drives are at the end of 1) an internal cable, 2) a |
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> case SATA-eSATA connector, and 3) an external eSATA cable along with |
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> whatever is inside the eSATA case. eSATA compatible ports must include |
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> hot-plugging logic. |
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> |
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> For cost/simplicity reasons chip manufacturers are free to remove |
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> hot-plugging logic from any port for which they don't intend eSATA |
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> compatibility. |
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> |
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> The logic and timing of the signals on SATA and eSATA cables is |
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> (TTBOMK) intended to be identical. What those signals look like at |
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> different places in the cable chain will be different. |
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> |
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> - Mark |
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|
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and you have sources to support that claims and did not just make it up. |
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