Speed ​​list until break through password

I often hear that "When there are many characters and there are many kinds of letters, the more breakthrough it is to break through," it is hard to hear, but when you set up the password, it is this chart that summarizes how difficult it is to be defeated is. In the case of only numbers, in case of only alphabet, in case of alphabets and numbers, calculated with various patterns including symbols.
Password Recovery Speeds
http://www.lockdown.co.uk/?pg=combi&s=articles

The breakthrough method exists in each stage from class A to class F,

A. 10,000 / s
When breaking the password of Microsoft Office file with Pentium 100 MHz

B. 100,000 / s
When Windows Password Cache (.PWL file) breaks at Pentium 100 MHz

C. 1,000,000 / s
To break passwords of ZIP or ARJ compressed files with Pentium 100 MHz

D. 10,000,000 / s
In the case of a typical configuration of a dual processor

E. 100,000,000 / s
When a high-performance workstation or multiple personal computers are linked by grid computing

F. 1,000,000,000 / s
Supercomputer

It is a standard feeling.

Looking at the results, you can see that 8 characters in mixed alphanumeric characters are very time consuming even at the supercomputer level. Still it will break through in about 80 days, so ideally it is desirable to change it regularly every two months or so in the future ... is not it? Somewhat impossible ....