Multiple choice general knowledge science & technology Which one is not a valid RPM(rotations per minute) value for Hard Disk Drives 7200 8700 5400 10000 15000 Reveal answer Fill a bubble to check yourself B Correct answer Explanation Standard HDD RPM speeds are 5400, 7200, 10000, and 15000 RPM. 8700 RPM is not a standard commercial hard drive speed and would be an unusual or non-existent specification in the market.