[FFmpeg-user] Best way to record video on a computer with a really bad CPU yet really good GPU?

[happysmash27 at vmail.me]

I am attempting to screencast using ffmpeg on my PC, but I have one 
problem: it uses too much CPU, even using `-crf=0`. Does anyone know how 
I can reduce this, either using a REALLY lossy format or using my Radeon 
RX 480? Even if it's not that efficient on my GPU, at least it will take 
some load off my Intel Core 2 Quad Q9450...

Also, for some reason using `-hwaccel auto` still uses CPU. Have I 
compiled it wrong? Or does it really need to use 100% of it...