ORICO 3529RUS3-BK 3.5" USB3.0&E-SATA Interface SATA HDD Enclosure Support RAID Funciton

Pros: Works fine in mirrored mode

Cons: Nothing much-a little pricier than others, but I've had other Orico units and they seem to hold up as well as any.

Other Thoughts: Re: speed as posted above: RAID1 is a mirror, and as such the write performance IS usually lower than a single drive (since it has to write and verify twice). Read is usually only improved if there are small files and it is reading several at once (and the controller supports splitting reads). But sequential reads will see no performance increase over a single drive at all. So the prior users experiences are inline with what to expect, but that isn't a negative- his expectations aren't reasonable.

Pros: USB3 + eSATA, modest size (one of the shortest 2-bay external RAID enclosures I've found,) actively cooled, tool-free

Cons: Configuration:
First, the process of changing the operating mode of this enclosure feels almost as archaic as the old jumper-designs of yester-year. There's a multi-stage switch on the back of the device. First one must reset the device by putting the switch to mode 0, holding down the "set" button, and power cycling. Then you move the switch to the mode you want, hold the set button, and power cycle again. If the device doesn't beep in the correct way, the mode has not taken.

There is no software tool to confirm the configuration - you have to "guess" based on the behavior of the activity lights on the front. Is it RAID0? RAID1? JBOD? Normal? If your OS reports 2x the capacity of a single drive, and copying a large file to the drive activates both activity lights, one can reasonably assume you've managed to enable RAID0. If the OS reports 1x capacity and both lights activate, you can reasonably assume RAID1. If the device reports 2x capacity but only one drive shows activity during a copy, then it's likely you've activated JBOD. I mention this because the method of changing its operating behavior is screwy enough that sometimes you'll think it "took" when in fact it didn't.

I'm using my device in RAID1 mode.

Performance:
I'm using 2x Seagate Barracuda 3 TB 7200RPM SATA 6 Gb/s NCQ 64MB Cache ST3000DM001. The device is connected to my eSATA port. RAID1 isn't PARTICULARLY processor intensive, so I expected 1.5x sequential read/write performance at minimum. Not so. CrystalDiskMark reports sequential read/write of 112MBs/63MB/s respectively, which is slower than a single drive. (1000MB write, avg of 5 repetitions)

Quality:
It's lighter than I would like. If you've ever handled a G-Drive made by Hitachi, this will disappoint. Still it's not flimsy, and the trays are indeed tool-free. My biggest concern is the fan, which started making the grinding noise we're all familiar with when a sleeve-bearing fan is failing after many years. It only took this fan two months to start doing this, and as of last week the fan has failed completely making my drives get incredibly hot.

When the fan was operating normally, it was loud enough to be noticeable, but not disruptive.

I'm on the fence as to whether I want to RMA this enclosure, or just get something else.

Other Thoughts: CrystalDiskInfo can't see past the enclosure to report SMART readings from the drives. Is this common in RAID enclosures? Perhaps it is, but still annoying.