Hard drives have been a big bottleneck in computer systems for quite some time now. Speeds on typical non-raid drives average somewhere between too slow and too darn slow. SSD's have been on the market for a while and prices are starting to drop. Some are becoming inexpensive enough for manufacturers to include them in laptops, and others are inexpensive enough for enthusiasts to dabble with. Initially sizes were very small, and 32GB wasn't uncommon to see running in the $500 (USD) range. We've done some scouting lately and we've seen 64GB drives from reputable manufacturers running in the $150 dollar range.
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Source: Bjorn3D