Are Two SSDs Any Better Than One?

In a few short years, SSDs went from exotic high-end hardware to a staple in most performance-oriented PCs and notebooks. As we already know, that's due to a few things. First, they're tremendously faster than hard drives, and orders of magnitude more responsive. Second, the price per gigabyte of NAND flash continues dropping thanks to advanced manufacturing and economies of scale.

Today, many 128 GB drives sell for less than $100. Stepping up to 256 GB often gets you even better pricing on a per-gigabyte basis (almost always under $1, and sometimes as low as $.60 per gig).

Now SSDs are at a point where enthusiasts have to make an important decision: do I buy one large SSD or do I grab a pair of smaller drives and stripe them in a RAID 0 configuration? This is largely an issue of performance. We know that single drives are hitting the limits of SATA 6Gb/s. So, are any of the workloads you're running that are taxing enough to necessitate the throughput (particularly in sequential transfers) two SSDs working cooperatively can deliver?

We're setting out to answer that question by testing the performance of modern SSDs at different capacities. Samsung sent over a sextet of drives: two 128 GB 840 Pros to test against a 256 GB model and two more 256 GB drives to test against a 512 GB version.

If you want more information on the 840 Pro, check out our launch coverage: Samsung 840 Pro SSD: More Speed, Less Power, And Toggle-Mode 2.0, along with our last experiment with these things: Is A SATA 3Gb/s Platform Still Worth Upgrading With An SSD?