This is a good presentation about using SSD with Cassandra. It's by RickBranson, DataStax http://www.slideshare.net/rbranson/cassandra-and-solid-state-drives
At Adobe we use SSD with great success to get RAM-like Read performance. 99% of all our requests are returned within 4 ms. You can see a presentation of that from Cassandra NYC 2011 Conf here: http://www.youtube.com/watch?v=tVbSeNkm8QM /Johan -- Johan Elmerfjord | Sr. Systems Administration/Mgr, EMEA | Adobe Systems, Product Technical Operations | p. +45 3231 6008 | x86008 | cell. +46 735 101 444 | jelme...@adobe.com