true. of course, a lot of the external SSDs on the market are bound by SATA interface like speeds anyway (even if they have fast external ports). so they won't

true. of course, a lot of the external SSDs on the market are bound by SATA interface like speeds anyway (even if they have fast external ports). so they won't be as fast as the internal flash memory in, say, a new iMac. the comparison is roughly: 500 MB/s vs 1700 MB/s http://www.apple.com/imac/performance/ http://www.apple.com/imac/performance/ an alternative to the garden variety external SSD would be an external PCI-E card housing (e.g. sonnet or akitio) connected through a Thunderbolt cable. now that's a lot faster. but, for that we buy an external housing in addition to the actual storage that goes into the housing. so this is more expensive than computers which let us install a PCI-E storage card directly inside the case. which Macs don't let us do easily or at all.