Expert's Rating
Pros
- Combines to two 2.5-inch drives in RAID 0, 1, JBOD, or Big Disk
- Fits two 2.5-inch drives in a single 3.5-inch bay
Cons
- Configuration issues with SSDs
- Disappointing SSD performance
Our Verdict
This cleverly disguised 2.5-inch RAID enclosure drastically improved the performance of our hard drives in RAID 0. But continuing problems with configuring SSDs leaves us unable to recommend it in that role. Still, for hard drives it works like a charm.
Talk about clever. StarTech’s 35SAT225S3R (available for $60 on Amazon) looks just like a 3.5-inch hard drive, but is actually a two-bay RAID enclosure for 2.5-inch drives. Those drives can be linked to form a single “Big Disk,” striped in RAID 0 for better performance, mirrored in RAID 1 for data redundancy, or treated like JBOD (just a bunch of disks), i.e. multiple volumes.
Subterfuge and camouflage are two words I rarely get to use in storage reviews, but that’s what came to mind when considering the prospect of hiding valuable SSDs in a less desirable guise? I was also hopeful the enclosure could goose the performance of cheaper, slow SSDs like the OCZ TL100. Sadly, configurations issues and disappointing numbers put an end to both those ideas. Deep sigh. Maybe the next iteration.
So there’s a reason StarTech calls the 35SAT225S3R a hard drive enclosure—and in this respect it excels. It makes it easy to harness those extra 3.5-inch drive bays you’re probably not using anymore, and drastically improves the performance of your slowish 2.5-inch hard drives when combined in striped RAID 0. And we like 2.5-inch hard drives, which, designed for laptop use, have caused us fewer self-imposed problems over the years. They also produce less heat and are quieter. Generally speaking.
Design
We’ve already told you most of what you need to know about the 35SAT225S3R—it looks like a 3.5-inch hard drive, yet handles two drives. But the simplicity of installing the drives also bears mentioning. All you need to do is slide the catch on the outside of the door at the front of the drive; pop open said door; slide in two drives; push the door back into place with minimal force, and slide the catch to lock. Nice design. We like nice design.

A low-pressure mechanism worked by the swing out cover/door makes it super easy to install drives in the 35SAT225S3R.
The other end of the unit is home to the SATA data and power connectors, as well as the four-way slide switch for changing the RAID modes. The unit is well-ventilated and slides right into any 3.5-inch bay to be affixed with screws.

The SATA connectors and RAID switch on the business end of the 35SAT225S3R enclosure.
Configuration and performance
With a pair of 500GB Seagate Momentus 5400.6 2.5-inch hard drives, everything was hunky-dory. We could put the 35SAT225S3R into any of the four modes without hassle. Sustained throughput took a decided turn for the better as you can see below. Good stuff.

Sustained throughput with 2.5-inch hard drives almost doubled in RAID 0.
Yes, the 35SAT225S3R is a great hard drive enclosure, but as I mentioned up front, the idea of using it with SSDs was too tempting. Sadly, switching to a pair of 240GB OCZ TL100 SSDs proved problematic. In our first attempt in RAID 1, the unit kept showing up as a 100MB volume.

We saw this far too often when trying to use SSDs in the StarTech 2.5-inch RAID adapter.
Finally, after switching to RAID 0 and pre-partitioning both SSDs as a single NTFS volume, the drive showed up as a GPT protected partition. Alas, Windows Disk Manager would not allow us to perform any operations on it. A quick trip to the command-line utility Diskpart allowed us to delete the partition and finally create a functional 480GB RAID 0 volume.

Though there was some improvement in speed with the OCZ TL100’s in RAID 0, it wasn’t startling, and it took a lot of troubleshooting to set up the array.
There was a definite uptick in the TL100’s throughput, but not nearly double, and possibly not worth the effort or the dough. Of course, the TL100’s are scows when it comes to sustained write performance, so I tried pairing two faster SSDs and ran into the same 100MB partition. The previous fix didn’t work and neither did wiping the drives so I decided to call it a day. So much for stealth and masquerade. While you might get your SSDs to work, you might not.
Conclusion
If you want to leverage a pair of 2.5-inch hard drives into faster storage for your PC, the 35SAT225S3R is a clever and very effective way to do it. But unless you’re up for a hassle and possible disappointment over getting SSDs to appear as an array, stick with hard drives here.