It's agonizingly slow because probably another process is more important like a second one running at the low priority level like Grid Republic or BOINC. Set the throttle to 100% and it should speed up. UD with HCMD as explained by the technicians runs at a lower than lower priority.

How to verify if a saved checkpoint was reached to prevent work loss, read this post. Hibernation is the ultimate solution. It does not require power, start your PC up much quicker and resumes all processes to the nanosecond exact same point you left off.

There's some reading here, but it gives some better understanding of the other projects of WCG as well.