Does the Mac bootloader recognise Windows on an external drive?

I'm trying to help someone install Windows on an external drive to use with their Macbook with OS version 10.8.5. I thought this method would be better than running Windows inside of the Mac OS as performance should be better (providing they have a fast external drive connector - have yet to find that out). I would hate for them to mash their Mac OS install by trying this out. Does anyone know if the bootloader will recognise this install and work without problems? Or is there something that would need to be done for this to work? Maybe this is not the best way to do it? Hope you guys can help out here. Thanks!

Edit: This is the model they have btw: http://support.apple.com/kb/sp658 It's got USB3 and Thunderbolt connections. Had a look at some speed tests and I think USB3 will be their best option as the performance doesn't vary much, plus it'll work out cheaper. But still unsure about the bootloader if anyone can help? Thanks.

anyone?

rEFIt on a mac definitely does. Not sure about Bootcamp.

It won't work. Windows doesn't like being installed on an external drive. I was looking at doing something similar myself. The best way to do what you want is to have a small windows partition, and mount your external drive under c:\games or similar.

Thanks for the replies guys! So maybe this isn't the best route :/ I will look for alternatives :)