Plex transcoding issue running on UNRAID with plex docker.

I am running Plex on a docker with Unraid on a DEll R430 Server with Intel® Xeon® CPU E5-2620 v4 @ 2.10GHz single processor and 32gb RAM. Plex keeps buffering during the playback of a movie. Is this processor not powerful enough?

“Is this processor not powerful enough?” Definitely should be im personally running Intel® Core™2 Duo CPU E7500 @ 2.93GHz with only 4gb RAM with is your transcoding settings at?