HA100 - Introduction 1.5 Managing the New Bottleneck

With multi-leveled CPU caches, data can be fetched to processor for processing faster.
eg
L1 Cache - 0.5 Nanoseconds
L2 Cache - 7.0 Nanoseconds
L3 Cache - 15.0 Nanoseconds

Comparing to the speed of 
Main memory - 100 Nanoseconds
Disk - SSD 150K Nanoseconds / HD 10M Nanoseconds

Traditional disk will be used as backups / logging  purposes and could eventually replaced by SSD.

Above is the summarized of my study and understanding for C_HANAIMP_12 certification preparation.
For more info, please refer to course material HA100 from SAP.