Over the years NFS has supplied NxWitness Ubuntu Linux NVR's with different "Desktop" interfaces. The Ubuntu Desktop is not exactly optimised for NVR use. It has significantly higher memory & cpu usage compared with NxOS images. It also has "bloat" software that uses OS disk space. Those extra resources are incredibly valuable on NVR hardware. Some of our support articles are specific to these versions, and the Screenshots below help to identify what version you might have.