1TB SATA SSD

What SSDs are you using? Also check your SMART readings. I've had really high IO pressure with ZFS Mirror on Crucial MX500. After upgrading to Samsung PM897 and PM893 the IO pressure went down significantly.

2 is not specific to a type. In general, the main problem of SATA these days, is that all the major players left the market. If you are lucky, you still can find somewhere an Crucial MX500 with quality TLC chips, otherwise in 90+% of cases it will be a QLC crap, which is literally slower than HDDs,

Buy a better GPU, You probably are not bottlenecking your CPU yet. What's your Ram look like? Are you on an SSD or m2 / NVME? The i5 has long been a GREAT gaming CPU, and the i5-12600k only sees marginal benefits over the 12400f at 1440p - unless you have $4000 for a whole new PC build, Target glass

The Strategy: A Systematic Teardown I started with a bare-bones system booting Unraid from a USB. I used the BIOS to disable every possible port (USB, NVMe, SATA, etc.) and let it idle for 5 minutes to establish a baseline. Then, I enabled the ports one by one to see the impact. Using a combination