ummmmmm ok how are large files going to cause the external to crash? seeing as an external hard drive is the same thing as a regular internal hard drive...the only thing that makes it external is the case. external hard drives are just as reliable as internals, although i have seen a few external hard drive enclosures go bad, but the disk is still fine. For the most part speed of the drive is going to rely on the buffer and the rpm , most drives will run at 7200rpm and most bigger drives have a 16mb buffer.. aslong as your using USB 2.0 it will be plenty fast, firewire would be even better...