Re: New computer advice
No. Both the 4000+ and the FX-55 use the ClawHammer core. And they both have a 1MB L2 cache. They are nearly the same processor, the 4000+ used to be called the FX-53. On top of having the maxed multiplier, the FX-55 does indeed have the multiplier unlocked, which makes overclocking easier.
An example of some low latency RAM would be certain types of Corsair XMS and other RAM. It's important to just look at the CAS timings of RAM when looking for low CL.