Order of magnitude usually refers to a 10x difference. Two orders of magnitude would be 100x difference.

(Sometimes the phrase is casually used to just mean "a lot", but here I think they mean 10x).

An order of magnitude is for example from 10 to 100, or from 1,000 to 10,000, so typically an increase by 10x or similar.

Reading is about 10 times faster than writing

(Very) approximately 10 times faster