[Ted L. Nancy]

I have a pair of 5-bay RAID enclosures. They are a few years old and have eSATA only (SIL4726). Is there a way for me to add USB (3.0?) to them? I feel comfortable adding the hardware, but I'm not sure what parts I need. Any help is appreciated.

[P]

USB to eSATA converters are reasonably common, but why would you want to do so?

[Ted L. Nancy]

I wasn't clear... I want to bypass the eSATA interface altogether - i.e. I want take the SATA off the drives and go directly to USB 3.0. My motivation for doing this is so that I can connect my RAID enclosures to my new Mac mini via USB. (They are currently connected to a HighPoint eSATA card that I installed in my 2008 Mac Pro.)

I found this... but it's the only one I could find, and the price is somewhat prohibitive for me.

I'm not 100% committed to this, but I am very interested in my options...

[P]

The drives that you use will still be SATA. The advantage with eSATA is that you don't convert anything - you just route the signals over a different cable. A USB 3.0 connection can never be faster, and it will in all likelihood be slower (although if you notice this depends on your workload), so the interface board above or an adapter will essentially be equivalent.

(There is a small wrinkle to this. USB 3.0 adds an optional storage protocol, USB Attached SCSI, which can improve performance immensely if all parts of the chain support it. I don't know if OS X supports that yet, but if it does, it is well worth looking for that buzzword in your converter)

Of course, if you want maximum performance, the path to go is Thunderbolt. There are some adapters on the market now.

[Ted L. Nancy]

Originally Posted by P 

Of course, if you want maximum performance, the path to go is Thunderbolt. There are some adapters on the market now.

SATA to Thunderbolt? eSATA to Thunderbolt? My first preference was to replace the SIL 4726 controller with a Thunderbolt card, to which I could hook up my 5 drives. I also looked for eSATA to Thunderbolt adapters. I wasn't able to find anything?

Is this even really possible? I understand you can chain Thunderbolt devices, but but since my SIL 4746 is a hardware RAID chip, how would the Thunderbolt handle the RAID? (I actually have the box set up as a JBOD, but I still need simultaneous access to all 5 drives.)

[P]

Thunderbolt is basically PCIe over a long cable, so what you'd do is connect the RAID controller directly to the PCIe bus as if it had been internal. Think of the Thunderbolt device as an internal RAID card with its own SATA ports, except in a box. The TB device simply implement its own SATA controller and RAID controller and connects as many drives as it would like. If you can't find a Thunderbolt controller for your RAID, another option would be Thunderbolt to the current eSATA. I suspect that the performance is limited by your HDDs anyway. USB would limit it further, however.

[mduell]

Are the drives actually saturating eSATA anyway?

[P]

The point isn't mainly performance, it's about connecting it a Mac mini, and hopefully not losing performance (as USB with UAS would).