ORIGINAL: Red Scholefield
Connect them all in parallel. This should give you a better output voltage. Collectively they will draw about 2 amps which is 10 watts total.
That was probably a typo (?), but hooking all four 1ohm resistors in
parallel will equate to
0.25ohm, which will draw
20A from the 5v line and generate
100w.
Personally, I'd start by putting just two or three of those 1ohm resistors in
series (2ohm or 3ohm total). The more current you draw from the 5v line, the more stable the 12v line will be, but you are wasting more power as heat.
[EDIT] Now that I re-read it Red, you probably thought he had four
10 ohm resistors...