How do I convert my videos to h265 without melting my current, shit, hardware

Transcoding anything >720p is painful.

I run ancient hardware for desktop/laptop >10yrs old apple stuff running linux. I consume media mainly via rpi4 or android.

What's a minimum level system capable of trans-coding 4k video to x265 in at the very least real time? Is there a tiny trans-coding device out there somewhere?

Would a NUC do? How old or new to churn out 4k x265

Can I avoid hardware? Are cloud gpu's a thing?