OK - new power supply it will be. I am going to ask the daftest of questions here again - what am I supposed to be looking for (wattege, brand, size of the fan) ? I have 3 year old Phenom x 4 (Agena) .

I've had a quick look around the computer case to see where can put more fans and there is one large available slot at the back. At the bottom front there's already a very large fan working all the time, judging by the distinct chill  on my feet.

Thank you all so much for your help and patience.

If it works, I shall not just buy Frontier - I shall steal, beg and borrow to buy Infinite...