HyperX PC4000 question

Sorry but I got a little confused.

My Kingston HyperX memory is a few years old now, it is a PC4000 capable of running in CAS 3 mode.

As I am doing more research it seems that memory which can be ran at CAS 2.5 have lower lower mhz speeds than my HyperX PC4000 which runs at 500mhz.

So my question is this:

Is my HyperX CAS3 500mhz faster or slower than a CAS 2.5 or even CAS 2.0 memory with lower mhz speed. And when I say "faster" I do mean real-world performance not a numerical speed.

Thanks for any info.

Well after reading more I see that the memory with CAS 2.5 or 2.0 timing does have lower mhz speeds thus the performance must be lower (just judging from the price), so I guess that my HyperX is still in the top 20% of memory performers. LOl I guess it is.