The Probook 640 G1 supports a 1,600MHz processor memory clock speed which is faster than most medium processor core notebook PCs that have been on the market for around the same time as it. Most similar spec portable PCs that were released more than two years ago support a 133MHz processor memory clock speed. In addition, this notebook PC supports 1 and 333MHz processor memory clock speeds.
A 1,600MHz processor memory clock speed is in fact the best supported memory clock speeds supported by processor amongst all laptops of a comparable age and type to the Probook 640 G1.
Amongst comparable types of notebook PC the worst supported memory clock speeds supported by processor is 133MHz.