Please don't compute speed-up like that.
Old time: 6 minutes (360 seconds). New time: 1 minute and 50 seconds (110 seconds). Speed-up calculated by article author: 1-110/360=0.694 (69.4% saved). Speed-up calculated by me: 360/110=3.27 (3 times faster).
Please calculate it the other way around. It makes great difference when you say you made something 10× faster than when you say you saved 90% of work even if both mean exactly the same thing.
Bruce Dawson has great article about this: https://randomascii.wordpress.com/2018/02/04/what-we-talk-ab...
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