Heya - welcome to the site

I'll have a pop at answering a few of your questions.

1) I don't run a quad core setup myself (3 machines instead), but given the chance it's the way I would go. Having everything on one box makes switching chars on deaths a lot simpler, and it helps with a lot of the setup.
Yes you can allocate WoW instances to individual cores. The client supports this natively I believe.


2) Lag - I do find that my toons appear different on each wow instance in relation to each other. Not much, but its funny sometimes. They don't usually stop though. Is this just when running about, or after combat? (as the follow will stop after combat and needs restarting)

I would advise setting the fps and graphics settings down to their minimum setting on the alt wow instance. That should help quite a bit.

My slave PC is I think the same as yours (A64 3000+). I didn't fancy running more than one WoW on it as the first one is a bit clunky, but there's not a great deal of RAM in the box (1GB I think). How much RAM are you packing in your machine, as that helps greatly with the performance as it avoids the client having to go to disk all the time swapping memory in and out.


Hope that helps - have fun with the boxing experiment. Speaking as someone who dualboxed with existing toons to start with, while that's fun, you should give some new identical toons a try out - that's a whole new blast (and might have you getting more accounts pretty soon )