"A flight simulation task was chosen for the assessment of the stimulants in a counter-balanced, within-subject design under four different conditions: baseline (no drugs), placebo, caffeine (200 mg), and modafinil (200 mg). The equal effectiveness of both drugs in abolishing the nocturnal drop in cognitive performance...."

From: Cognitive Performance during Sustained Wakefulness: A Low Dose of Caffeine Is Equally Effective as Modafinil in Alleviating the Nocturnal Decline
by Dagan Y, Doljansky JT. Chronobiol Int. 2006;23(5):973-83.

Provigil is a controlled substance. Cafeein isn't. Yet.