I have the above system with duel core 1ghz cpu and have seen a 1.25 duel core cpu for sale will this make much of a difference of would i be best installing a 1.8ghz single core cpu?

Thanks

Hi Caver!
Go for the 1.8 single cpu (Sonnet?) since double 1.25 cpu module are usable only on PowerMac MDD.
I can tell for sure that is really fast.. If only it had L3 cache....!!

You can't really use the 2nd CPU under MorphOS so the 1.8GHz will be faster even if the 2x1.25 would fit into the QS.

1.8GHz in a QS is reaaaaaaaaaallllll nice ;)

if i went for a 1.8 cpu do i have to get another heat sink or will the duel one still fit?

All CPU upgrades I've seen sofar come with their own heatsink.

The one that sits on my dual 1.8GHz is actually smaller than the ones that belong to the stock 733MHz modul (but than it's copper instead of aluminum and add 2 fans).

If your modul comes with out a heatsink, apply thermal grease, add stock heatsink a fan and a way to monitor temperatures atleast during "burn in".

thanks all for the advice