CMS means? Basically if your previous card worked normally, psu can handle it then there shouldn't be any problems. Sounds weird but how about borrowing his PSU to see if your 7870 can be powered up using that?
And one thing I forgot to ask : did the vga's fans spin when you turn on your pc?
Yes the fans spin on the graphics card. I tryed my friends psu and the same result occurred, however the graphics card works on his computer. I am super confused but I think it's a motherboard/bios issue. I was planning on buying the biostar tz77xe3 because I've heard good things about it. So I guess I'll just purchase it sooner than I was planning.
Right, something's wrong with my eyes atm... If you do want to OC by a great amount like 4.8ghz+ and have the desire to grab a good 50$ cooler for that then the Z77 E4 would be the better choice. If around 4.5ghz is good ( good enough to gain much higher FPS in games, if you ask me ) then just grab the E3 and a decent cooler like Hyper 212 EVO.
I was thinking around 4.5 or 4.7 for my CPU so I bought the zalman cpns10x performa cooler. I really don't know what differences there are between the e3 and e4 but which would you recommend for overclocking between 4.5 and 4.7?