Yes, THROUGHPUT is a Scrabble word!

Letter values in Scrabble US: T 1, H 4, R 1, O 1, U 1, G 2, H 4, P 3, U 1, T 1.

Is it a valid word?

THROUGHPUT is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

output relative to input; the amount passing through a system from input to output (especially of a computer program over a period of time)