laptops are wrong tool for this job, generally. maybe someone will provide specific guidance
I'll suggest you search this forum for lots of recent discussions on this same subject (OSB settings for under-powered computer)
Short answer - use OBS's Auto settings, and beyond that requires your own testing, as OS setup will have equally large impact
To keep overall CPU utilization down
- keep base and output resolution the same
- don't use Studio Mode (2X rendering)
- make sure unnecessary OS services/tasks/processes not running . If need be.. turn off eye candy in the OS