Quad core processors and quad graphics solutions are already available, but is it time for quad hard drives yet? While two hard drives are a must have for any enthusiast looking for performance (RAID 0) or data safety (RAID 1), four drives are the minimum to get the best of both worlds.

Using four hard drives you can setup a so-called nested RAID array, which consists of a RAID 0 and a RAID 1 configuration used together. The result is called RAID 0+1 or RAID 1+0, depending on how you lay out the two RAID modes. You get the net capacity of two hard drives in RAID 0+1, as the performance RAID 0 is mirrored on the other two drives, or two RAID 1 sets are striped in RAID 1+0.

Nearly all RAID controllers with connectivity for four hard drives support RAID 0+1/1+0, but the more sophisticated option, a RAID 5, requires a more advanced controller solution. Enthusiast chipsets offer RAID 5 capabilities; alternately, you can look at the market for RAID adapter cards. RAID 5 works like RAID 0: it distributes data blocks across all but one of the available hard drives. The controller then calculates redundant parity information across the block that was written, and stores it on the remaining drive. Should one hard drive fail, the data can still be accessed by reconstructing the missing blocks using the parity information. RAID 5 has two drawbacks, however. First, it requires quite some computing power to deliver high performance. Second, you have to find a drive count that balances performance and the risk of a drive failure.

Why am I telling you all of this? Simply put, 2.5" hard drives are an alternative to 3.5" desktop drives when it comes to storage density, or performance density. One 5.25" drive bay will only hold a single 3.5" drive, but the Quadra Pack allows you to run four 2.5" drives in the same space. As you can imagine, a fast RAID solution across four drives will provide up to 180 MB/s of maximum sequential transfer rate, something you cannot possibly achieve with 3.5" drives when there are space constraints (think of low-profile servers or SFF computers).

The Quadra Pack offers four drive bays for 2.5" SATA drives, allowing us to set up either a RAID 0+1/1+0 or a RAID 5 configuration, or two independent RAID 0 or RAID 1 arrays instead. The drives have to comply to the standard drive height of 9.5 mm for notebook use - 12.5 mm drives such as the Fujitsu MHV2200BT won't fit into the trays. All SATA cables are mounted permanently, so you cannot exchange them by shorter or longer ones. The solution is, however, hot-swap capable if your SATA controller is.

Enhance Tech placed a pretty noisy fan into the back of the Quadra Pack, which effectively kills our idea of using it for low noise, high throughput, high density storage solutions. So... we have to say thumbs up for a cool product, but thumbs down for not making it quite right.

Pros:

• High performance density by supporting four 2.5" drives in a 5.25" drive bay.
• Uses standard 9.5 mm 2.5" SATA drives.
• Installs easily.
• Can be paired with any suitable SATA controller.
• High coolness factor.

Cons:

• Unreasonable fan noise.
• SATA cables cannot be exchanged.