Odd RivaTuner results

[OrdinaryPhil]

The Problem:

 

I have recently installed MSI Afterburner and RivaTuner to learn how they work. After a few hours of tinkering I got it configured the way I wanted and set up a simple overlay. Among the items I added to the overlay are the standard current FPS, 1% Low, and 0.1% Low. I loaded up Space Marine 2 and toggled the overlay and everything seemed to be working as I expected... at first. The current FPS was in the 130-140 range, the 1% lows were about 125, and the 0.1% lows were 99 to 101. Now this may seem obvious to anyone with experience in RivaTuner, but the 1% and 0.1% figures fluctuate less than the current FPS figure, which seems to update about once per second. The average values seem to update less frequently, about once per 5 seconds or so.

Anyway, I toggled the recording off so that the low values were no longer being tallied, and made a few changes to see how they would affect the performance. I toggled the averages back on and the values dropped significantly. the 1% lows were suddenly 85, and the 0.1% lows were in the 40s. The current FPS value was largely the same, and I perceived no change at all in smoothness. I exited the game, exited RivaTuner, then opened them back up - the results were similar. Still having 1% lows at 85, and 01.% lows around 40. I toggled the recording off again and back on... and the values dropped once again. Now I was getting 1% lows around 65 and 0.1% lows around 32!

There did not seem to be any actual difference in performance. The current FPS was always between 130-140, but the low values just keep letting lower every time I toggle them off and back on again... eventually settling in at 60 and 30 respectively. There are no other apps running apart from what you would expect; Afterburner, RivaTuner, Steam, SM2.

I'm assuming this is some kind of configuration error on my part but I am not familiar enough with RivaTuner to troubleshoot it so here I am

Here are some of the relevant hardware details:

EVGA Z690 Dark Kingpin
Intel I9-13900k

ASUS x Noxtua RTX 4080
32GB DDR5 6400Mhz
2TB SK Hynix Platinum
Alienware 27 360hz OLED 1440p
Windows 11

 

Here are some relevant non-hardware details:

I've made some extensive deviations from the default configuration.
HyperThreading, TVB, and TB 3.0 have been disabled in the BIOS.
Intel "baseline" limits are all enforced.
Virtualization has been disabled.

Intel iGPU has been disabled.
All E-Cores are disabled.

These may sound like strange changes, but at end result is actually quite nice. Windows sees my CPU as an 8-Core CPU with 32MB of L2 cache. And with all the E-cores disabled, no iPGU, and no virtualization, I can run at a constant 5.5Ghz across all 8 P-Cores and never break 70c with a simple air cooler.

I've been using this configuration for quite a while so none of the items above were changed after RivaTuner was installed.

ANy advice?