I know that the operating frequency of a computer's CPU, while still important, is not the only relevant factor for measuring a computer's overall performance today. For example, memory is also a major factor, and even with its ultra-fast operating frequencies, it often is still slower than the CPU, so when I next upgrade my computer, I plan to purchase faster memory for it (of course, I know that a mechanical hard driven is the slowest component in a modern computer, but I currently cannot afford to purchase a solid-state drive, plus that subject is one for a different thread).
I have conducted my own research on memory speeds and timings, but I am still uncertain which measurement is more important overall for determining the memory's performance, so I shall ask the other users here for advice. Is it better to have memory with a low operating frequency and low latency (such as 1,600 megahertz with a latency of 6, 7, or 8) or memory with a high operating frequency and high latency (such as 1,866 or 2,133 megahertz with a latency of 9)? And why are no or few memory modules with both high frequency and low latency? Does having a high operating frequency inevitably increase the latency of the memory, as well?