I want it to be as quiet as possible.
It will have an SSD plus one 3.5" HDD for data (speed is not important, silence is)
The graphics card is fanless and there is one slow, quiet, 20cm case fan.
Which HDD is quietest? I can't afford a 1TB SSD

(I have spare WD green drives but don't like the way they close down every few minutes)
Your thoughts?