Sorry Alex, but you have not provided anywhere near enough info to answer your question. the real answer is - it depends
And there may not, depending on your situation, be a single answer.
- Some games especially behave differently (use CPU and GPU differently) meaning settings that may work in one situation (ex psychovisual & lookahead) won't work in another.
this is my most important point... depending on workload to be captured, you may need to change your OBS Studio settings
and don't ignore impact of background operating system processes, and video card driver settings
- and what is 'best' for one person isn't best for another.
- and best quality depends on movement, color depth, etc. And then workflow (for example, do you plan to video edit Recordings later? if so, what does your editor require?
And you are wrong to think PC isn't an issue. going for maximum quality can bring a US$10-20K workstation to its knees. There is no workstation that can't be overwhelmed when it comes to capturing demanding workloads at high 'quality'. Anyone who claims otherwise is lying or ignorant
So, start with this thought process
- what is your desire/requirements (not a simplistic 'best' ... that is sort of like asking what is best quality car?.. there is no one valid answer to that question ) Answering your question is more like solving a multi-variant calculus equation
- assuming by 3g, you actually meant 3Gb/s (presumably fiber optic ISP connection) not 3G wireless (which if cellular, then bandwidth, latency, and jitter will absolutely be a limiting factor) You can most likely stream at a bitrate (and other settings) higher that your content delivery networks will accept. So start with what the maximum settings your CDN (content delivery network, ex Twitch, YouTube, FB, etc) will accept. That will give you one workload boundary
- Then run your most demanding workloads (games or whatever) doing real-time hardware resource utilization monitoring ... at that point you should know what spare resources you have to work with
- Also, if gaming, see any number of recent threads on stuttering and drop in FPS... recognize impact of mismatch monitor refresh rates vs game FPS, and OBS capture FPS rate (hint, best to be kept at even multiples, meaning possibly lowering monitor refresh rate and capping game FPS to get better quality)
- Then, depending on usage for Recordings, that will determine how resource impactful settings selection you can make.. for example most people aren't heading with HDR, deeper color depth, etc; so increasing any of those values will be wasted (and may actually cause problems).
