Hi, I'm NOT a musician but a computer geek.
The first article is pretty basic so let me put my 2 cents:
Modern processors, CPU's, have cores and threads, a two core four threads CPU will be "read" by the operating system as 4 CPU's but won't be as efficient as a 4 cores 4 threads that's also "read" as 4 CPU's. Examples an Intel i3 is a two core four threads while the i7 is 4 cores 4 threads.
The ammount of Cache memory and Front Side Bus, FSB, speed will benefit the over all processing.
As for memory, the more the merrier, but if you match the FSB of the CPU with the FSB of the memory there won't be any delays on the transit of the information.
But remember, an 32 bit OS would only accept 4 GB of RAM, so go for a 64 Bit OS.
An finally the Hard Disk, SSD are the fastest kid on the town, and the more expensive. So you can get a 10,000 RPM SATA 2, 32 or 64 KB cache memory HD and get a pretty good performance.