At what speed / voltage did your 5850 ended up at ?  

In the same vein, (4x5850)

Here is how I build my miners,  These take very little space, provide good cooling and are easy to carry around. (no I don't stack them)

More , http://imgur.com/a/bRbDZ



CPU is some Pentium 4 crap, Board is some other crap found in the trash, PSU is OCZ 850 gold.  Plastic box ~4$ at Staples. + 2.5" 80gb for Windoze.