Of course, SSD storage remains more expensive than mechanical storage. Price comparisons vary, but it seems fair to say that the cost of mechanical storage is dimes per gigabyte, while the price for solid-state flash storage is dollars per gigabyte, or a factor of between 10 and 20 more expensive. But the performance of SSD is so superior that an astute buyer should consider solid-state flash drives for any but low-end servers.
A Sun executive was quoted as saying that a 32 GB flash drive enabled about 5,000 write and 30,000 read operations per second, as opposed to about 180 write and 320 read operations per second on a mechanical drive spinning at 15,000 RPM -- an improvement factor of 28 and 94 respectively. For server use, where I/O speed is critical, the performance differential clearly outweighs the price differential.
Meanwhile, thanks to volume production of solid-state storage for consumer products such as cell phones and MP3 players, the cost of flash storage per byte has been falling at 50% to 70% yearly. The end result is that pundits are predicting that magnetic and optical storage will begin to fade away even in the desktop market, to be replaced by flash memory. That may be true at the high end, but elsewhere mechanical drives are surely too cheap and familiar to fade away any time in the next decade. And they're superior for backup, since a ghost of the data survives on the platter even if the drive fries.
Sun also noted SSD energy consumption is about one-fifth that of mechanical disks and even RAM. With all the current talk of locating data centers in Siberia or Iceland simply to avoid paying for air conditioning, the advent of inexpensive solid-state drives could help ease the data center energy crisis.
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