my 8 pin atx is 43 cm and the atx 24 pin is 62cm is the 24 long enough?
24-pin is more than enough, But cant say the same for the 8-pin.
It is definitely not long enough to go around the back of the motherboard tray. You will have to either go on top of the motherboard or get an extension.
http://www.overclockers.co.uk/showproduct.php?prodid=CB-066-AK&groupid=701&catid=1428&subcat=1689


