Is SATA3 backwards compatible with SATA2?

I have another replacement PC from Ebay (Dell OptiPlex 755 as before), and preparing to send it off to the computer shop for modifications. I am wanting to upgrade to a better mobile-rack (Syba SY-MRA55006) and a SSD, but both are SATA3 and I think the PC is SATA2. Will these work, or do I need to find SATA2 components?

 

@ trimis:-

Nah, you should be fine. Mixing different SATA interfaces is very like mixing different speed RAM sticks; they'll simply throttle back to the slower interface.

Illustration; the elderly Compaq desktop tower I'm posting this on dates from around 2004. It was built at the time when SATA was just starting to appear in the marketplace, so consequently this mobo has both SATA-1 ports and IDE ports on the same board.

When I inherited it from my sister about 5 years ago, it still had the original WD Caviar 'Black' 160 GB IDE/PATA drive it came with originally. A couple of years ago, the drive was beginning to show signs of finally packing up (at 14 yrs old, it'd had a good run!), so I replaced it with another WD; this time, a 500 GB WD Caviar 'Blue'. By this time, of course, you could only get SATA-3 drives.....but I plugged it into one of the two SATA-1 ports, and it's been as good as gold to this day.

Data transfer is still double the speed of an IDE drive.....

(*shrug*)

Just my two-penn'orth, FWIW.


Mike.

 

The Optiplex 755 is SATA2? I have a 120gb HP SSD in mine and i think it runs ok.

 

Yep, USB 2.0, which I think means SATA II. Just yesterday did a Google search for its specs, and found out it has eSATA connector inside, but no sign of an eSATA plug outside...guess that means it has eSATA capability. Might ask the computer shop about sticking in a plug or socket or whatever its called.

 

I can still buy SATA 2 hard drives off Ebay. Most are used or refurbished (about the same I'd guess) but occasionally new, and last year I got one from NewEgg:

https://www.newegg.com/western-digi...m_re=hard_drives_3gb/s-_-22-136-284-_-Product

Slightly off-topic but is there a problem with XP Pro and external hard drives that connect via eSATA? There is stuff all over the forums of people saying that XP users need to only use external hard drives that connect by USB 2.0, as eSATA requires special drivers and such.

 

TBH, I don't know. I've never tried connecting via eSATA. My external Seagate desktop drive connects via USB 3.0, thru a USB 3.0 adapter card I've got plugged into the one PCI-e slot I have (graphics cards won't work in this; some of the pins at the far end are damaged, but with the adapter card being a 'shortie', and sitting at the top end of the slot, it misses these).

It's essentially a SATA3 'Barracuda' drive, but the enclosure these things come in contain a 'bridge card' at the back where the connectors are, which converts the SATA plug to a USB 3.0 socket.....not hard to do, as both SATA and USB are 'serial' devices, of course. And it works really well, too.

You'd be more likely to find USB 3.0 drivers than you would an XP one for eSATA.


Mike.

 

Exactly what would I need/have to do to get USB 3.0 on my Dell OptiPlex 755?

 

Basically, the difference betwixt SATA & eSATA is the shape of the plugs/sockets. The eSATA connection cable is more robust as it is exposed to external bumping/moving/pushing/bending/coffee spills!/etc. But its still just a standard SATA plug on the business end.

 

SATA 2 is roughly half the speed of SATA 3. A Sata 3 drive plugged into a SATA 2 port will deliver SATA 2 speeds, roughly 150 MB/s whereas a SATA 3 port would deliver roughly 250 or so.

I have a couple old MacPros with SATA 2 ports, and that's what they deliver. For a spinning drive (a conventional HDD) that's not a big problem because their delivery capability is less than SATA 2 so they will run at the same apparent speed as they would on a SATA 3 connection. SSDs won't, though.

 

As noted above, an esata port is just a different end on the otherwise same sata cable (esata is designed to make sure there is no interference and can withstand the plugging and unplugging). So anything esata is just like being sata. And esata is actually faster and more robust in my experience, much faster than even usb 3.0, because it is native sata--no drivers, layers, etc--just speed!

 

You can add a pcie card like this one from startech and install the drivers:
https://www.startech.com/en-us/cards-adapters/pexusb3s23