just how noisier are EE GPU's..?

I was planning on buying an External Exhaust GTX 460 SOC until someone said they are noisey?

is this true?

we wish to avoid noisey PC if possible and so would go for different card, the PC in question is only for Flight Simulator X and no other games - this game does not bring top end GPU's like GTX 560 etc under full load (so ive been told) - so I think for us a decent GPU but one thats 'quiet' is what we would like.

BUT...if they are not that noisey then maybe not

thanks