Home > Data Protection > PowerProtect DD Series Appliances > Dell PowerProtect Data Domain SISL Scaling Architecture > Future scalability
SISL in DD OS takes the pressure off from the disk I/O as a bottleneck, so the remaining system design is CPU-centric. That is a good thing. Over the last 25 years, CPUs have improved in performance by a factor of millions, while disks have only improved by 10x or so. CPU vendors appear poised to continue these benefits well into the future. It is reasonable to imagine that each doubling of cores could mean Data Domain systems can improve speed by about 50 percent. It is also straightforward to imagine methods to integrate controllers to create multi-node aggregates for larger datasets. A fingerprint-based dialog between controllers can be lightweight. Some approaches exist today that prove the merit in this scalability approach, but they do not solve the price/performance challenges addressed by SISL. Instead, they just make it possible to connect all those spindles needed for good performance. By solving those problems at the outset, the Data Domain architecture provides the foundation for cost-effective aggregation in the future.