Qtier 2.0 IO Aware is a feature available in QTS version 4.3.3 or later. With IO Aware, QTS reserves 25% of the SSD tier capacity in a Qtier storage pool for faster access performance. If data in the capacity or high speed tiers experiences a high number of read or write requests, QTS immediately moves it to reserved SSD space instead of waiting to move it using auto-tiering. This improves random I/O performance, offering performance similar to having an SSD cache.