You may be running low on CPU power, however, there is another common cause of the slow screen redraw symptom:

The MSPMono plug-in is a DirectConnect "inlet". It is looking to make a connection with reFuse. Until is sucessfully makes that connection, it will be eating extra CPU cycles, and the screen redraw rate in Pro Tools will slow way down.

The fix is to only activate as many MSPMono plug-ins as you are actually using (for however many channels of audio you're routing from reFuse). If you want to open a Pro Tools session previously saved with MSPMonos, but you don't want to launch reFuse and Reason, disable the MSPMonos by control-Apple clicking on them.

If, at this point, the problem is not solved, please contact us for further support.