Why You Can’t Use CPU Clock Speed to Compare Computer Performance
 

Shopping for a new computer? Don’t pay too much attention to CPU clock speed. “CPU speed” was once an easy, if not completely accurate, way to compare two computers’ performance — just compare the GHz. But not anymore.

Modern CPUs are more than fast enough for most basic tasks, so you’ll also want to look at other things when it comes to comparing performance. For example, does the computer come with an SSD or a slower magnetic hard disk?

http://www.howtogeek.com/177790/why-...r-performance/