After a couple of weeks I am noticing that my heatsink cooling fan cannot run at full speed when the Z-axis is moving.  The z-axis also seems to move slowly and the entire printer slows down irregularly during most of the start up process.  Usually after the first layer prints the issue seems to to mostly go away, but prints are taking like 20-30% longer than estimated by the slicer and I am afraid that the power supply is failing.