April 20, 2010, 8:17 AM — by Loyd Case, PC World - Solid-state drives are all the rage. Since SSDs have no moving parts, they're more rugged and shock-resistant than standard hard drives--which makes them perfect for laptops that get bumped around a bit. They offer fabulous read performance, too, though their write performance varies; random small writes can be very fast, but long writes of large block data (as you might have with continuous video recording) can be slower than on traditional hard drives.
However, upgrading to a solid-state drive isn't as easy as buying a drive and throwing it in your PC. Here are a few tips for picking out the right model, making sure that it will work with your setup, carefully cloning your old drive, and keeping the install process clean and painless. (Don't forget to read "How to Switch to a Solid-State Drive" for more advice.)
The main drawback of a solid-state drive is the cost: Per gigabyte, SSDs are much more expensive than standard hard drives, which have come down dramatically in price in the past several years. While it's easy to find an inexpensive laptop with a 160GB, 250GB, or even 320GB hard drive, a high-quality 256GB SSD would likely set you back over $700. That's a high price to pay, particularly if your current laptop or netbook is a fairly low-cost unit.
SSDs come in two major types: SLC (single-level cell) and MLC (multi-level cell). An SLC SSD stores data as one bit per flash memory cell, while an MLC drive stores two or more bits per cell. As a result, MLCs are less expensive than SLCs at the same capacity point, since you need fewer physical flash memory components for greater capacity.
The downside is that MLC drives are slower than SLC units, though usually still much faster than regular hard drives. You'll typically find SLC drives in data centers and workstation-class environments, where the greater cost is mitigated by gains in productivity and reliability.