The ThinkPad W540 supports a 1,600MHz processor memory clock speed which is faster than most portable PCs of a comparable age and spec to it. Most many processor core portable PCs that came out around the same time as it support a 133MHz processor memory clock speed. This portable PC also 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 similar age and type to the ThinkPad W540.
Amongst comparable types of notebook PC the worst supported memory clock speeds supported by processor is 133MHz.