All I need is a new processor?

[AnyOldName3]

The main two dolphin threads will use up two cores completely. This means it works fine on a dual core, however, it leaves no room for other processes, or the minor threads of dolphin (which are 1% or less of dolphin's load). On a quad core, these can be allocated to the two spare cores, so if you've got a lot of other stuff running in the background, it may be slightly faster.

There is, however, another, even more important use of the extra cores. When using LLE audio emulation, this can be separated into a third main thread, and so when LLE on thread is enabled, it will use a third core, and will therefore make the thing faster.

Basically, quad core is better, so you'll be wanting an i5, not an i3.

[NaturalViolence]

Quad core cpus provide about a 20% performance boost over dual core cpus with same clock rate and microarchitecture running dolphin in dual core mode. Those background tasks and minor threads add up.

[admin89]

Good CPU for dolphin : G860 , i3 2120 , i5 2300 , i5 2400 , i5 2500k , i5 3570k
AMD Phenom II , Intel Core 2 duo , Core 2 quad....are outdated technology .
Edit : AMD Llano 3870k is as fast as core 2 quad 9550 or 9650 . If you overclock to 3.5GHz , most games will run well . Demanding games like Last Story and SMG are out of the question though