I am trying to understand how to compare speeds in English. I have two types of devices that do the same thing. Their performances are measured in operations per second.
Let's say I have Device A that operates 17 times per second and device B that operates 12 times per second. Is it correct to say that:
Device A is faster than B by 41.7%?
because (17 - 12)/12 is approximately 0.417. How should it be (17 - 12)/17 = 0.294? That means the following is correct
Device A is faster than B by 29.4%?
Also I wonder what are some other ways I can say one device is more/less efficient than the other?