plex Plex Server/NAS & CPU Hardware Accel. Transcoding

Hypnotoad · March 27, 2019

I'm doing research on building a NAS to support Plex streaming/transcoding, as well as simple file storage (backups). Right now I'm trying to focus in on the video transcoding for Plex, and making sure it's not going to be a big problem. On Plex Media Server's CPU recommendations page, they recommend (very roughly), a CPU with a PassMark score of at least 17000 for 4K HDR (50Mbps) transcoding to 1080p (10Mbps). I want to make sure I can support at least one stream at this quality, but I am also trying to not spend so much on a CPU.

Plex Media Server also has a page up about hardware accelerated streaming, on which they state that for any OS, they support HW accelerated streaming with Intel's Quick Sync Video feature. However, they do not draw any lines between hardware accelerated streaming and CPU PassMark scores, or indicate if there is any correlation there.

My expectation is that using an Intel CPU which supports Intel Quick Sync Video would lower the PassMark score required for 4K HDR transcoding, but I'm not sure by how much or what I should expect. Basically, I can spend $410 on an Intel Core i7-9700K, which has a PassMark score of 17241, but can I get away with a cheaper CPU like the Intel Core i5-9400, which also supports Intel Quick Sync Video, and still be able to transcode 4K HDR video?

EDIT: It seems like the main factor in HW transcoding is the iGPU. It appears that Intel's latest is the UHD 630? In that case, I'm wondering what is the cheapest CPU I could get away with that has the UHD 630 iGPU? Or put another way, how much work needs doing that isn't HW accelerated which depends on things other than the iGPU? How important is the number of CPU threads and clock if it already has a UHD 630?

EDIT2: Would an Intel G5500T perform the same with regards to HW accelerated Plex transcodes vs. an i7-9700K?

EDIT3: https://pcpartpicker.com/user/krcm0209/saved/2cdNQ7 Playing around with a potential build. I am open to feedback for improvements.

Hypnotoad · March 27, 2019

On the topic of many HDD support (with unRAID)... would it be better to buy a motherboard with lots of SATA ports by default, like the ASRock Z390 Extreme4? Or should I just get the cheapest motherboard (Gigabyte H310 A Micro) that the CPU will work in, and get a SATA PCIe expansion card?