If the Synchronous Buffer Commits is disabled, then Windows lies to an application and tells the application that it's writing data to the drive when Windows is actually caching the data in memory. This increases disk-intensive application performance. However if you happen to lose power when it is disabled then the data in cache will not be written to disk , and that data may be lost. It is normally used only for troubleshooting by advanced users. Such a loss would apply to currently unsaved data and may not worry some.
Compression employs special drivers to squeeze more data into the same volume of disk space.
Disk compression can gain you 1.5 to 2 times the amount of current hard disk storage. Older systems typically have small disks and compression can be a life-saver. However there is, inevitably, another side to the story. Compression reduces performance . It increases the risk of data loss .