CAS latency hasn't been measured directly in nanoseconds for some time now. It is now measured in clock cycles.
Yah, so to compare two different sticks of RAM you have to multiply the time/cycle by the number of cycles. Which gives you (wait for it....) time!
Which the parent did, to point out that all these "new" memory technologies haven't been decreasing the RAM latency much at all. RAM latency is still a _VERY_ important part of overall execution performance. Particularly for single threaded operations reading RAM in unpredictable manners. Cache misses are overwhelmingly the single largest optimization variable for modern applications.