An x86 Processor – A high-end chip that (if more than 2.0Ghz in frequency and dual/quad cores) will be able to handle transcoding with relative ease across all your Plex enabled devices all the way upto 1080p High Definition and is even popping up in 4K UHD Devices. These are typically found in the majority of QNAP and higher-end QNAP devices.
An ARM Processor – These are less proficient than the x86 chip and will struggle transcoding at 1080p and may even have difficulty at 720p High Definition. These are typically found in the home and small business units (QNAP 2 BAY units, as well as WD My Cloud and Seagate NAS). However, they are still a very prominent CPU and an excellent NAS processor in general. It is HIGHLY recommended though that you look at Realtek 64bit ARM newer generation ARM processors, as these can support Plex Media Server, but without transcoding.
A PPC (Power PC) Processor – Very much the lower end of the spectrum. These Processors are not particularly capable of any kind of real-time transcoding and will struggle to give you the optimal output via your Plex Media Server to your Network Enabled Device. We generally do not recommend them for in a Plex Media Server environment and are found in the low end, budget NAS devices.