Disagree, the i7 advice is good, if you want to run the newer Golden Tee stuff at full speed you'll need one for example (and even then you need to put it in the lower-res mode to ensure there are never any frame drops)
Old AMD chip? even the current high end AMD chips are a joke for MAME...
The stuff with discrete sound being added (eg. Kid Niki drums and soon Congo Bongo) start to need i7 level tech too, they DON'T run at full speed on my older core2 with the full discrete sound enabled. The trend for increased CPU requirements is only going to continue as the emulation is further refined.