I'm looking at Dell 240w power bricks and three PNs come up. I'm assuming GA240PE1-00("PA-9E Family") and LA240PM160 look the same, but I'm guessing different manufacturers since some of the the GA240PE1-00 also have a Flextronics label, and LA240PM180 is the rounded-edge later design with a chip in it? Do they all perform the same?