cycle per second vs cycles/second

cycle per second and cycles/second both are nouns.

Word	Noun	Adjective	Verb	Adverb
cycle per second	Yes	No	No	No
cycles/second	Yes	No	No	No

As nouns, cycle per second and cycles/second are synonyms defined as:

cycle per second and cycles/second: the unit of frequency; one hertz has a periodic interval of one second (named for Heinrich Rudolph Hertz)

Other synonyms of cycle per second include cps, cycle, hertz, Hz.

cycle per second (noun)	cycles/second (noun)
the unit of frequency; one hertz has a periodic interval of one second (named for Heinrich Rudolph Hertz)	the unit of frequency; one hertz has a periodic interval of one second (named for Heinrich Rudolph Hertz)