Personally i use only like this:
For Quality
CPU Preset= Veryfast
Profile=main
Tune=film
For Performance
CPU Preset= Veryfast
Profile=main
Tune=fastdecode or zerolatency
And work very well for me with a very very poor system pc. I am streaming from a laptop from 2009 (HP DV5) , i stream in 360p 30fps and its work very well, my processor its used like 45%.
This is what the modes do:
- film – intended for high-bitrate/high-quality movie content. Lower deblocking is used here.
- animation – intended for cartoons, etc., where deblocking is boosted to compensate for larger, flat areas. More reference frames are used.
- grain – this should be used for material that is already grainy. Here, the grain won't be filtered out as much.
- stillimage – like the name says, it optimizes for still image encoding by lowering the deblocking filter.
- psnr and ssim – these are debugging modes to optimize for good PSNR and SSIM values only. Better metrics don't necessarily mean better quality though.
- fastdecode – disables CABAC and the in-loop deblocking filter to allow for faster decoding on devices with lower computational power.
- zerolatency – optimization for fast encoding and low latency streaming
