I've had this sitting around for a few weeks and I've finally freed up some time to play with it.
SanDigital makes over a dozen different enclosures and it can easily get confusing which one to get.
You may have seen some on sale combined with eSATA cards. Take note, many are simply JBOD (Just a bunch of disk) enclosure box that require an eSATA port with port multipliers to function. Otherwise, you only see the first disk. Hence, the reason many come with eSATA card bundles. Port multiplication is not common on many eSATA interfaces; including most laptops and motherboards. Those cards often require some sort of software to run them in RAID.
So it is very critical you are aware of the difference when you shop for these type of enclosures.
Luckily, this is not a JBOD enclosure. This has a built in RAID controller and when it was priced the same as a JBOD box, I decided to pick one up. This device supports RAID 0,1,3,5,10 and as well as JBOD. These go for $179-199. I was fortunate to pick this up for $99.
The box is rather tiny and minimal to accommodate 4 drives. They drives do not use a tray but do require you to fasten them down with screws.
The back takes a standard prong power plug (power supply is internal). There are two interfaces - eSATA and full size USB 3.0. There is also a dial and reset button to set the RAID modes. The front side has some little ventilation but I would prefer that the front door provided better airflow.
Setting the RAID mode is a straightforward affair. You simply turn the dial to the mode you want. You can also overcome the dial settings through the RAID manager application.
Front indicator shows activity and which drives are failing. In this case, the 3rd drive has gone bad.
The Raid Manager app shows you status and has other options to create and delete new RAID sets.
The application also provides diagnostic and notifications controls. I've read that the email settings may have some problems with SMTP servers using START/TLS authentication. I did not test to find out. Unfortunately, I could only get the Windows version to run. The Mac app didn't appear to work for me. This may be a Mountain Lion compatibility issue.
There may be a firmware update and I'll look into it and update this post later. For now, I would not recommend this as a USB 3.0 RAID enclosure. I've been reading other brands and make have similar problems.Customer reviews on Newegg and Amazon corroborates similar experiences. However, under USB 2.0, I didn't notice any problems.
Unlike most of the customer reviews I've been reading, I've been getting the 200 MB/sec sequential read transfers in various testing when using eSATA. The drives I used were 500GB 7200 rpm Seagates.
Windows appears to perform better (using benchmarks as well as real copies).
I only tested RAID 0 and RAID 5 but I did not see much of a performance loss going to RAID 5. The 4k/512k was about 1/4 slower in writes but the sequential read/writes were similar to RAID 0. In short, copying large files saw little loss while your random files will be faster under RAID 0 as it should be.
Here is a RAID 5:
and RAID 0
This box is cheap enough to get if you are using it with eSATA. I would not recommend for USB 3.0 use.
If you are a laptop user without eSATA, I recommend using a USB 3.0 eSATA adapter like this NewerTech one I reviewed earlier.