GFlops is credit based and credit is, well .... known to go all over the place. That said, the PCZika chart, visit my sig link, does not indicate anything wild, but for that supply dip some days ago due work batching issues. Maybe your device had a bout of wingman that were claiming low and passing part of the bucket to you.

I have experienced a this in the past. It turns out there was a svchost process which was using the Windows update service which was eating about 50% of the processor time. It turns out there was a missing update which caused the update service to churn and get nowhere. I tried several things and eventually one of them fixed it, but I am unsure which item in myriad of Microsoft solutions was the magic one.
Cheers

Its well known that both Vista and Win 7 have this update problem and Microsoft do not seem to be interested in fixing it.

Feels to me that they are trying to force peeps to Win 10, otherwise they will have to put up with sluggish machines, which could also be insecure for long periods of time, while trying over and over to get the required updates.
Eventually the updates do arrive, but it can take days while hogging the CPU cycles.

Have seen a 24% decrease.
- 12 August: 53.4 points per hour (based on 57 Valids)
- 21 August: 40.5 points per hour (93 Valids)

EDIT: changed "Augustus" to "August" (since "augustus" is Dutch)

I have noticed this variability over many different projects, particularly OET and Zika. My average points performance on all three of my computers seem to dip and rise in unison regardless of any external factors. At first I thought that this was a phenomenon of the number of WUs in PV Jail but that has been fairly constant recently. Another factor that may be significant is my ambient temperature which changes by + or - 15C across a period of a week or so. Also when WUs are taking more time, the number of hours held in PV Jail increases which could also explain the dips.