You can improve simulation run time by deleting extraneous output reporting. Remove any lines that say Output:Variable,*
Be careful to not use the * key for report all especially for surface variables or for node variable reporting. If you need to report a surface or node variable call out the node or surface explicitly.
Also, you are best off to perform shorter simulations of one to two weeks in summer and winter until you get the simulation working properly. Note that you can include multiple RunPeriod objects to accomplish this
Finally, if your simulation is still taking a long time and when you run for the two week periods, and if you are getting a lot of unmet load hours, you are likely to have some HVAC iteration problem due to incorrect application of sizing or setpoint parameters