There is a command-line software tool that really saves the day for me, it’s called cpulimit which is available in the Software Manager.
CPULimit, allows you to force a process (running software program) to only use a fixed percentage of CPU time in your computer. It’s handy if for instance, you wish to launch the Firefox web browser, and only allow it to use 10% of your CPU.
In my case, I use it to limit a much hated plug-in, Adobe Flash (Please can that die now, it’s the scourge of the web!)
The software is not difficult to use, but there is a learning curve. The link above will take you to the developers web site, where you can learn how to implement this wonderful tool.