 One SSD controller manufacturer, SandForce, does not use an external DRAM cache on their designs but still achieves high performance.Such an elimination of the external DRAM reduces the power consumption and enables further size reduction of SSDs.Another component in higher-performing SSDs is a capacitor or some form of battery, which are necessary to maintain data integrity so the data in the cache can be flushed to the drive when power is lost; some may even hold power long enough to maintain data in the cache until power is resumed.