The EliteBook 840 supports a faster memory clock speeds supported by processor than most portable PCs that are a comparable age to it. This portable PC supports a 1,600MHz processor memory clock speed, whereas most portable PCs of this age and type support a 133MHz processor memory clock speed. This laptop also supports 1 and 333MHz processor memory clock speeds.
A 1,600MHz processor memory clock speed is actually the best supported memory clock speeds supported by processor amongst all similar spec notebook PCs that have been available for more than two years.
The worst supported memory clock speeds supported by processor amongst comparable types of portable PC is 133MHz.