Quoted from John_I:

Why would you do this? Seems like a lot of extra work removing the old fan for no benefit. The way I look at it, I'd rather leave the original fan in there. With the external fan there, the original should never come on and the air will flow through it just fine. If for some reason the extra fan loses power or fails, the original fan will be there for backup and you will hear it come on and know something is wrong...

Quoted from John_I:

You missed the point. Once the external fan is in place the original fan will never come on. The original fan comes on when the game heats up and runs for a bit and then goes back off again. When you install the larger, quieter fan on the adapter, you connect it directly to power so it is on all the time. The game stays nice and cool and the original LOUD fan never comes on. This way you don't have to go through the hassle of removing or disassembling the power supply to get to the original fan. Makes the install way easier.