Is all power supplys the same size?

Is all power supplys the same size? or do u need to find one the fits specialy into your case?

Typically the type of P/S has stayed in the boltup fastening standard, as where it secures to the case itself, with increased power outputs some of the higher end ATX P/Ss are longer than the 5 1/2" and extend further into the case, my Silverstone OP1000W is 8 1/2" and barely left me with room between the back of it and my DVDRW.

Note: Cablewise the length is even further, for the cables out the rear of the P/S to make the turn needed for clearance!

So if you're talking in the power range from say 300W to around 750W, ATX P/Ss all seem to stay in the original configuration length, beyond that wattage, depending on the brand, double check the P/S length to the available case dimensions.

are, dammit, are!!!!!