Notice I said to an extent, as games only utilize 2 cores and you only need like 3.0 ghz to run any game perfect, while if you had 600 mhz ram you would see some big problems, I am sorry you misunderstood something.
The post I quoted indicated a fundamental misunderstanding of what choices matter the most when trying to improve gaming performance.
The relative 'speed' of RAM matters very little compared to the performance of the CPU. Main thing to keep in mind is the performance of each component must be balanced against it's cost relative to the total cost of the build. Sure, paying for an amazing CPU but skimping on the memory is a poor choice, but when it comes to how much you should spend, the bulk of your budget should be allocated to the GPU and CPU.
My personal rule of thumb when putting together gaming builds is that 20-30% of the budget should go to the GPU, another 20-30% on the CPU, 20% on the motherboard, 15% on the Powersupply, and the rest on the memory and extras. Of course, I adjust these guidelines from time to time as needed.