Oh, hai there!
I've recently come across this idea on operating my PC efficiently. This setup involves a separating of the huge multimedia files like "movies, setup for demos, music etc.", from the personal data and tools.
While browsing the harddrive the other day, I noticed:
Those thousands of letters, self written program code, savegames, (small files that I've put lots of work into, but very small in size) looked totally unimportant next to 800gb of multimedia files, which take up about 99% of space.
The Setup:
1) The huge multimedia chunk goes onto an external USB harddrive.
2) The personal files and what I'm working with, will come into an older PC, which I built from spare parts, and only has a 50gb drive. This one needs only 70 Watts power to operate.
3) The fast PC, which is currently attached to Flatscreen TV, will wait there for watching TV and gaming in 1920x1080. It uses 520 Watts power.
4) The router, which will connect both to internet. Last not least, the router can connect an external harddrive with USB, but can keep downloading when both PCs are turned off.
The Benefits:
I can save up to 70% on the electricity bill, because you know you don't need one quadcore with 5.1 soundsystem beeing turned on all the time for surfing and browsing forums.
I can download stuff to this router with the harddrive attached, and/or let it act as FTP server with just 10 Watts power consumption.
I can start downloads on the "little brother", to use it then on the gaming PC.
And I need not leave the 520 Watt gaming beast turned on anymore for the whole night while I'm downloading stuff...
Summary:
80$ for 1 external hardrive enclosure, 1 router and 1 wireless usb adapter.