command processing overhead vs access time

command processing overhead and access time both are nouns.

Word	Noun	Adjective	Verb	Adverb
command processing overhead	Yes	No	No	No
access time	Yes	No	No	No

command processing overhead (noun)	access time (noun)
(computer science) the processing time required by a device prior to the execution of a command	(computer science) the interval between the time data is requested by the system and the time the data is provided by the drive