This is my PSU atm >Micro ATX. The set up is: Gigabyte GA-H55N-USB3 XFX HD 5870 1GB Intel Core i7 870 2.93GHZ Kingston ValueRAM / 2GB 1333MHz PC3-10600 DDR3 x2 And a 500GB hard drive EDIT: will not overclock anything I'm gonna cram it into a Silverstone sg05
Barely, even though it says 500w it is only capable of outputting 324w (14A+13Ax12v) from it's 12v rails which should give you a little headroom but I can't find any decent reviews that will actually vouch for a Colours IT PSU. If you do intend to use it i'd only use it for a short period of time until you get a reputable PSU.
but i already have the XFX 5870 in another set up with a AMD Athlon x2 64 5000+ in the SG05. So im just wanting to upgrade to a new motherboard and a new CPU. The Micro ATX can power the things i have now. But will it power a i7 870?
if your having problems craming this all in with a decent psu (which should be one consider as one of the most vital parts of your build, never skimp on the psu) maybe try looking at a larger case?
A Silverstone 450w ST45SF SFX should power it, mars-bar-man installed one in a mini-ITX build with a GTX460 here: http://forums.bit-tech.net/showthread.php?t=190391. Scan have them for £62.24: http://www.scan.co.uk/products/450w...r-80-plus-bronze-85-eff-18db-eps-12v-80mm-fan. You also qualify for free delivery from Scan: http://forums.bit-tech.net/showthread.php?t=186923.
The mATX PSU I'd get would most likely be this: http://www.silverstonetek.com/products/p_spec.php?pno=ST45SF&area=usa http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story3&reid=196 With the key difference being that this one comes from a respected brand, is reviewerd, and most of all is capable of 432 W to the 12V line.
I agree with Jipa on the PSU chose, as others have said, dont skimp on the PSU, it is the most important part of the build. I am silverstone fan, they make great kit esp. for HTPCs.