You can go into the CLI and run the command to ensure that the cache is enabled. What I would recommend to do first is try syncing the clocks in the GUI. Then after that if you look at pages 189-192 it lists a number of commands. The main ones you would want to do is the: mirrorCacheEnabled=TRUE writeCacheEnabled=TRUE Here is the link in case you have any questions. support.dell.com/.../CLIMR.pdf Let us know how it goes.
I even had BOTH RAID controllers replaced for brand new ones from Dell Still cache not enabled show in the log (and nothing to say that it IS enabled) Latest firmware. Yet the status of the unit shows as green Optimal  Seb
Cache not enabled on MD3600i