"i have an external hard drive (640 gb) i can use this for storage but can i run games put onto it " Yes, one of my kids has steam installed on an external drive, it does not appear that much different in level load times from the pc next to it. (USB limits you to around 20 mb/sec, internal could hit 100+ mb./sec in benchmarks. In real world the difference is a lot less. A good spinning disk drive does 100 or 200 random 4K operations a second max. That's less than 1MB/sec => 200 x 4K = 800K/sec < 1MB/sec.)
fwiw:
http://www.bbc.co.uk/news/technology-15534614 "...The Thai floods are set to cause up to a 30% slump in hard disk production in the last three months of the year compared to the prior period, according to IHS iSuppli.
A report by the research firm said hard disks have already risen in price because of damage caused to factories.
It warned supply shortages may continue throughout the first half of 2012..."