Over the past two years, I've gone through a steady process of upgrading the many notebook PCs that pass through my hands, from conventional spinning drives to SSDs. Before that, I upgraded some of my older notebooks—like my still-trusty Dell D620 Latitude—from the laughably small 80 GB drive it arrived with in 2008, to larger conventional 2.5" hard disks, typically 250 to 500 GB in size. At one point, I even upgraded my HP HDX 9203 ("The Dragon") from the original 250 GB drives it shipped with to some very nice WD 750 GB Scorpio Blue drives, and then replaced one of them with an OCZ Agility 2 SSD.
As a result, I have seven or eight 2.5" hard disks in my inventory, all of which are still working just fine. And from time to time, I even find myself with older or unused SSDs available, which I hate to see sitting idle. That's how I found myself looking around for good solutions to put these drives back to work.
During my stumbling around, I discovered a handy product category that fills a 5.25" drive bay and accommodates four to six 2.5" drives. Many of these products advertise themselves as RAID cages (see this $50 Newegg product listing) and most of them provide in-cage, hot-swappable drive caddies that plug into both SATA and SAS connections from the back of the cage to motherboard (or RAID controller) drive ports.
I ended up purchasing a $55 SNT device (the same one is now available for $50) that has served me very well in my Windows 8 desktop test machine. Right now, that drive enclosure houses four 2.5" drives: one is 750 GB in size, and the other three are 500 GB each (of course, these are nominal drive sizes, and Windows reports 465 GB for the smaller disks, and 698 GB for the larger one).
I do a lot of project work, and back up numerous different test and production machines, so access to numerous smaller drives (all of my 3.5" drives are 1 to 2 TB in size these days) actually makes it easier for me to remember what's where and to access things more quickly.
Working with a RAID Cage
The SNT unit depicted in Figure 1 includes four hot-swappable drive caddies (each has a blue plastic pop-up tab in the photo). These are easy to remove during run-time, so it's quick and convenient to swap drives in and out of the housing as needed. The enclosure is made of surprisingly heavy brushed black aluminum, and includes two reasonably quiet 40mm fans that pull air in through the front of the unit and vent it out the back (into the computer case).
Documentation for the unit is scanty, so I had to figure out by trial-and-error that the yellow modular ports on the back were for SATA and the gray ones for SAS (but this took only seconds to determine for a single drive, after which I was good to go).
Figure 1 Front view of the SNT SNT-SAS-425 unit
Figure 2 shows the layout of the SAS (above) and SATA (below) ports for each drive bay, with the two fans in between and a molex power connector at the far left. The DIP switch goes left for SATA and right for SAS (and was set to SATA by default).
Figure 2 Rear view of the SNT RAID cage
I have several boot images set up on SSDs that I can use to perform alternate boots on this test machine (this does require me to jump into BIOS and change the boot priority order, but that's easily managed). The hot-swappable caddies make it easy to pop out one drive for another, so I can get pretty creative in setting up and managing multiple boots for this PC without having to muck around with multi-boot set-ups and installation.
Overall, this unit has proven to be incredibly handy, not just because it enables me to make effective use of surplus 2.5" drives but also because it makes it easy to swap out drives I don't need at the moment for others I want to use for various projects, boot scenarios, backup, or testing. With the addition of a nice inexpensive 4-way RAID controller card (such as this $90 HighPoint PocketRAID 2640x4 PCI-e x4 model), it's also easy to turn the drives in the RAID cage into a bona-fide RAID array as well.
But Wait...There's More!
And I mean more in this case quite literally. Well-known PC case, ventilation, and power supply vendor Thermaltake makes what it calls an HDD cage (though there's no reason why you couldn't use SSDs inside it as well or instead of conventional hard disks). Its MAX-1562 model manages to squeeze in six 2.5" drive caddies that fit inside a conventional 5.25" drive bay enclosure.
Figure 3 depicts this minor marvel of small-scale engineering.
Figure 3 The Thermaltake MAX-1562 squeezes a half-dozen drives into a 5.25" bay.
The Thermaltake MAX-1562 retails for $75 at Amazon, so it ends up costing the same per drive to house 2.5" units as you pay for the cheaper SNT unit I purchased. I haven't tried one of these enclosures, but I read that it's important to steer clear of drives that are 10 mm or more in thickness to ensure a proper fit.
Because most notebook drives are 8 mm-9 mm thick, this shouldn't be a problem for most people with 2.5" drives they wish to use. And indeed, you can buy slim-line drives as thin as 7 mm (with smaller capacities and higher costs), but larger capacity 2.5" drives—especially 1 GB drives—tend to be 10 or 11 mm thick. You'll probably want to measure the drives you wish to use (or look up their detailed dimensions online) before choosing such a high-density drive cage.
Put More 2.5" Drives to Work
If you still build systems or have a desktop PC with an unused 5.25" drive bay, a drive cage like the ones described in this article may be a good addition to the usual collection of build components.
It certainly makes it much easier to mount and use 2.5" SSDs in modern systems, without having to install a typical 2.5"-to-3.5" housing in a 3.5" drive bay instead. And with the combination of a RAID controller, you may find yourself exploring realms of disk performance you never thought possible on your desktop PC!