That's why I said "risk £30" as a cheap PSU is a risk - although they should of course be reasonable and it is a 750W so has lots of headroom above what you need.
Personally I would probably spend more like £60 and get something even higher quality.
There are some comments on Toms Hardware
relating to this. Sounds like there is a risk and someone is suggesting a bodge to get a common ground for the PSUs. Have to say if I valued my house I probably wouldn't risk the potential fire from something going wrong with a home bodge.
EDIT: The more I read the less having 2 PSUs looks like a good idea. There is a product called add2psu
which purports to make this safer to do but as it costs $20 itself it seems buying a 500W PSU would be the far better option.
Edited by ian72 (Tue 28-Oct-14 09:26:19)