SATA vs eSATA

I'm doing a new build and my case has an eSATA port on the fron panel.
The motherboard has a couple of unused SATA ports, but nothing
specifically designated as eSATA.

Can I connect the front-panel eSATA port to a plain old SATA port on
the motherboard, or are these really different things? It looks like
the connector will work, but I wonder if there are electrical
differences that would make this a bad idea.

(I don't really have any plans for using eSATA, so if this can't be
done, it's no big deal. But if if would work then I figure I might as
well do it.)

TIA for any advice.

Reply-to address is real
-- John

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John said:


I'm doing a new build and my case has an eSATA port on the fron panel.
The motherboard has a couple of unused SATA ports, but nothing
specifically designated as eSATA.

Can I connect the front-panel eSATA port to a plain old SATA port on
the motherboard, or are these really different things? It looks like
the connector will work, but I wonder if there are electrical
differences that would make this a bad idea.

(I don't really have any plans for using eSATA, so if this can't be
done, it's no big deal. But if if would work then I figure I might as
well do it.)

TIA for any advice.

As a rule, you can connect eSATA ports on your case to onboard SATA
ports. They're electrically compatible, the problem is with poorly
written drivers that fail to cope with hotswap situations.

This can be an issue with native eSATA ports too, not just converted
ports.

--
The nice thing about standards, there is enough for everyone to have their own.

On Tue, 12 Feb 2013 09:49:06 -0500, John
wrote:


I'm doing a new build and my case has an eSATA port on the fron panel.
The motherboard has a couple of unused SATA ports, but nothing
specifically designated as eSATA.

Can I connect the front-panel eSATA port to a plain old SATA port on
the motherboard, or are these really different things? It looks like
the connector will work, but I wonder if there are electrical
differences that would make this a bad idea.

(I don't really have any plans for using eSATA, so if this can't be
done, it's no big deal. But if if would work then I figure I might as
well do it.)
There are some external drives,
Seagate Free Agent GoFlex Ultra-Portable, for instance that require
+5 on what is normally the data only cable for operation.
There might be some that need both +5 and +12.

Therefore you should check for eSATAp (eSATA with power) and/or
USB/eSATA combination ports.

The eSATAp ports come in both +5 and (+5,+12V) versions. Maximum
current at each voltage should also be considered.

TIA for any advice.

Reply-to address is real
-- John

John wrote:
I'm doing a new build and my case has an eSATA port on the fron panel.
The motherboard has a couple of unused SATA ports, but nothing
specifically designated as eSATA.

Can I connect the front-panel eSATA port to a plain old SATA port on
the motherboard, or are these really different things? It looks like
the connector will work, but I wonder if there are electrical
differences that would make this a bad idea.

(I don't really have any plans for using eSATA, so if this can't be
done, it's no big deal. But if if would work then I figure I might as
well do it.)

TIA for any advice.

Reply-to address is real
-- John

SATA and ESATA are identical on protocol.

There is a slight difference in the electrical (analog) specs.
ESATA has a bit more budget on the difference between
transmit level and min usable receive level. And that
allows a slightly longer cable to be used.

http://en.wikipedia.org/wiki/Sata#eSATA

Minimum transmit amplitude increased:
Range is 500–600 mV instead of 400–600 mV. --- launch amplitude

Minimum receive amplitude needed:
Range is 240–600 mV instead of 325–600 mV. --- receive sensitivity

Maximum cable length increased to 2 meters (from 1 meter)

The first two items there, is what allows the cable to be longer.

Some chipsets claim to support both SATA and ESATA, but
I've never seen any detail as to whether something has
to be programmed to make it work. It would seem they
just run in ESATA mode all the time, ready to work with
a longer cable if one comes along. Because I can't see
any info to suggest a register needs to be flipped to
do one or the other.

If you have some ESATA setup of questionable heritage,
you can try using a shorter cable than the max stated
by the ESATA spec, as a crutch. If you think you're
getting transmission errors on the cable, the shorter
cable may help a tiny bit.

Paul

On Tue, 12 Feb 2013 09:49:06 -0500, John
wrote:


I'm doing a new build and my case has an eSATA port on the fron panel.
The motherboard has a couple of unused SATA ports, but nothing
specifically designated as eSATA.

Can I connect the front-panel eSATA port to a plain old SATA port on
the motherboard, or are these really different things? It looks like
the connector will work, but I wonder if there are electrical
differences that would make this a bad idea.

(I don't really have any plans for using eSATA, so if this can't be
done, it's no big deal. But if if would work then I figure I might as
well do it.)

TIA for any advice.

Reply-to address is real
-- John


Thanks all for the help.

Since I have no eSATA devices at the moment, I buttoned up the case
with the front-panel eSATA cable not connected. But it sounds like I
can hook it up if I need it and it'll probably work. I'll keep that
in mind.


Reply-to address is real

John