Quote - I haven't noticed much difference, maybe a couple of seconds in sim and render times?

Uh...  :-(

Thanks anyway.

No, I have a fairly recent computer (Athlon 64 4000 MHz), the question was if and how I can improve it still further. Waiting over a week for a render to finish is long... I'm not that young anymore, I fear I will die before I've rendered half the pics I have in mind...  :o)