Sitting here watching my clock display in WD and the only time I see any lag is at the even minute change. It appears that WD is updating graphs or log files every other minute and I do not see up to 3 seconds before it starts counting again. Also, at the hour change over I see the clock lag again for about 7 seconds, I assume WD has more housekeeping that needs to be done. Accessing the harddrive and writing data is the slow spot in the process and has little to do with computer horsepower. Other items can also effect WD processing, ie. webcam, tide calculation, etc.
How often is your system writing to the log file? My log file has an entry for each minute and I do not know if WD is capable of writing more than one entry per minute. I’m trying to understand how your system is missing data. Can you post a clip of your log file that shows where/when the data is missing?