I watching closely the last

I watching closely the last couple days since all the motherboard updates.  Playback is better, but I still get a 1/2 second pause or video goes to slow motion about 2 – 3 times in a 1 hr show.  Each time I can rewind and replay, but there error does not repeat itself.  Each time the error seems to accompany hearing the hard drive rumbling. 

Since I can replay and it works fine it indicates to me the video is recorded properly.  In the past I did replace the drive with another.  There was an improvement for a week or two, but it returned.  All drives so far have been gren drives.  Should I be looking for a 7200rpm drive to store recorded video?

I still have not updated my bios.  I had some issues in the bios recognizing the updated bios file so I have a ticket in with Gigabyte.