Alpha.Geminorum

I have a Unraid server used to manage Media across mine and my family devices (multiple laptops, tablets, desktop pcs), so it's maily used for storage/streaming of movies and tv shows, and backup of photos and other media. When I built it in 2018 I thinkered a bit with some VMs, but then I got another PC to do the gaming/heavy lifting, so now it's only running Plex and Usenet/Radarr/Sonarr etc dockers. The specs are: Phanteks Evolv ATX Asus Prime H270 plus intel i5-7400T 2x 8GB Corsair Vengeance DDR4 3x 6TB WD RED for data 1x 8TB WD RED for parity 1x 250 GB M.2 cache for appdata and dockers 1x 1TB M.2 cache for downloads / streaming I have 18TB usable of storage, and now I'm closing to 16.5 fully used, so I was thinking of getting another 6tb Wd Red plus (the cmr ones) and be done with it for another couple of years. That would be the fastest and cheapest solution, but I was also considering getting a more recent CPU (12100) /Mobo (H610) and move to fewer bigger HDDs (I've seen recently 16 and 18 tb Exos at just 30/40 € more than the 6tb wd reds) - remove the old hdds and move to 2x 16/18 TB + 1x Parity, and be done for the long run. The REDs are all CMR, I got them before WD started getting shady with the 6tb ones, and they've performed well for these past years, being on almost 24/7; the only thing that annoys me a little is that the 8tb parity one gets uncomfortably hot during parity, around 56-58c, while the 6TB ones never went above 42c, even in the summer - the disks are spaced and with two 140mm fans blowing on them. Giving the recent energy price spike here in EU I'm also considering if getting a more recent CPU/fewer HDD would get cheaper to run compared to a older CPU/ more HDD, given that CPU usage is usually just around 10% for most of the time. What would you suggest? Thanks!