I am currently using an iMac 2.4gHz 24" with 2gb Ram. I have issues with it as recently the power to the USB bus went (rogue device blew it) and I have to use powered USB port expanders to be able to continue using all my peripherals. Not ideal and in fact cannot boot up with them all connected. No-one has been able to confirm or deny whether the USB Bus is on the motherboard and therefore stupid to replace (i.e. same price as new iMac) ....anyway I am thinking of a new machine and the 2 shops I have spoken to seem to think I am talking a foreign language and have had no help there. I run the following devices USB (all requiring USB power) Midisport 8x8 (USB power required even though it is a mains powered box. I do use every port, in and out) M-Audio Keyboard External hard drive WIDI interface. Firewire devices Focusrite Saffire 40 Alesis Firewire 16 (These last 2 devices are run as an agregated device - I like to use the Alesis on "live" studio recordings - single take stuff and recording full rehearsals. Effectively 8 tracks at 3 hours each. I really want to replace the USB hard drive with firewire rackmounted raid array hot swap drives (prob 4 x 1Tb drives). The existing set up is really running close to the wire and I think adding more devices in this way will become too much for the present iMac especially if hard drives and Audio interfaces are using the same port in a firewire chain. So I want to scope my Mac options, max up my CPU power, RAM and hard drive options and have plenty of firewire and USB ports. Trouble is I do not know the Mac hardware range at all. Do all Macs run Leopard? Has anyone any experience of non Apple machines running the Mac O/S. I read an article on it once but not heard of anyone doing it for real. I am prepared to spend a few thousand if that's what it costs (and that's not counting the firewire drives - they can cost more than my current iMac). Can I have your opinion on which way to go for a new heart to my studio.