It sounds like your desktop has other programs using a large portion of your processing power. If you want to run 10+ bots at a time you should configure your OS to run only what is required by OSBot and nothing else.
There is a lot of potential differences in the configuration of your two machines. I would recommend comparing power settings, services and startup programs between your laptop and PC as a start.
All of that said, your CPU and RAM are only parts of what makes a machine run well. Things like drive read/write speed, power supply, drivers, and general config can be just as, if not more, important.
I'd recommend reducing the amount of programs you run on startup as a start. Assuming you're running Win10 you can do that in the Task Manager. Then go to add/remove programs and just uninstall everything you don't use (be careful not to remove stuff like Java and .NET Runtimes). If you don't check often, you'll be surprised by how many things are eating up your resources.