There are many variables that will make an application run better and faster and setting a higher priority in the task manager would be the last one. You can take this test yourself now and little difference you will notice or none at all. This response from SuperUser.com explains how this configuration works:
For your application to run faster and in fact you feel a difference, the solution would be to invest in hardware: faster CPUs with more cores, storage with faster read and write rates, faster RAM.
Best Regards,