Solid-state drives (SSDs) have always been sort of extreme. They are, for the most part, extremely fast and, unfortunately, even more extremely expensive. I wouldn't mind having one that's slightly less fast so that it could be more affordable, and the Crucial M4 just about fits that bill.
The drive performed well in our testing, though it was slower than others. Compared with traditional hard drives, however, it's still easily two or three times faster. In terms of pricing, it's the most affordable 2.5-inch SATA 3 SSD we've reviewed.
At around $440 for 256GB (or 210 for $128GB), the M4 has a cost per gigabyte of approximately $1.72, compared with the $2.26 of the OCZ Vertex 3. Its top 512GB version is even better, with just a $1.56 cost per gigabyte, compared with the $3.76 per gigabyte of the 480GB Vertex 3.
Now, obviously, this is still in no way cheap enough for most of us, but so far this is probably the most affordable SSD on the market that will still wow you with its performance. Ideally, I would love to see SSDs' prices go down to around a dollar per gigabyte. Hopefully, that's the near future.
In the meantime, if you want to find out exactly why it is such a good deal, check out the full review of the Crucial M4.