"Numbers everyone should know", from Google's Jeff Dean, has part of the answer: http://julianhyde.blogspot.com/2010/11/numbers-everyone-should-know.html http:

"Numbers everyone should know", from Google's Jeff Dean, has part of the answer: http://julianhyde.blogspot.com/2010/11/numbers-everyone-should-know.html http://julianhyde.blogspot.com/2010/11/numbers-everyone-shou... Where do SSDs fit in? Not sure, but I've heard SSD read latency can be as low as 30,000 ns (compare to HDD seek time of ~10,000,000 ns), while SDD sequential read rates are still within one order of magnitude of HDD read rates. YMMV depending on your access patterns. Lots of random access? SDDs a clear win over HDDs because of the seek time penalty. (I'd guess lots of random access is almost always the norm, except for certain specialized server workloads.)