Weird DX 12 observation in test

[CrabbyR]

I am currently using a RX 7800 XT with a 5900X cpu...I have run the benchmark suite many times with updated drivers and with the latest versions of Passmark. I have noticed that the DX 12 test always gives me a score of 90fps, never deviating always 90, whats most odd about it is that my prior card a 6700 XT used to give a score that varied between 99 and 105 fps on the DX 12 test.
Same hardware OS same everything only the graphics card is changed
But the most interesting thing is today while running the test suite, an annoying windows update notification box appeared in the lower right corner while running the test at the beginning, The score in DX 12 jumped from the standard 90 fps to 179 -180 with a final score of 179. So after the test I closed the box and tried to repeat it ....Locked down to 90 fps again.
Can anyone shed some light on what going on there?

[Richard (PassMark)]

Some possible things to check if V-Sync (or AMD FreeSync) is enabled. V-Sync limits your frame rate to match your monitor's refresh rate. Check if FreeSync is enabled in the AMD Radeon Software or in the monitor’s settings. Try disabling it and see if your FPS increases.

[CrabbyR]

Unfortunately that was disabled. I have been trying to figure this one out for a while now. One thing for certain is that software is capping the FPS in the DX 12 test to 90 fps. That windows update overlay
enabled or disabled something that allowed the FPS to double I am actually more suspicious of windows 10 at this point. 90 FPS is fine for everything but it is sort of annoying that the passmark benchmark cannot actually measure the real performance of the graphics card. If you have any other ideas let me know, If I do figure it out I will post the solution...I`m sure that other people are experiencing the same thing. The DX 12 scores seem quite low on many high end cards

[David (PassMark)]

What is the refresh rate of your monitor? Is it 90Hz?

[CrabbyR]

Actually it is a 4k TV...with a 60hz refresh...
Not sure if that is relevant though because as stated above the graphics cards are capable of anywhere from 90 to 180 FPS depending on other factors that I am trying to identify. Like I stated above that overlay caused it to double from 90 to 180 FPS

[David (PassMark)]

Average for this card in the DX12 test is in fact 93. So 90 isn't such a crazy number.
But there is a very very broad distribution of results for this card. Meaning there are a lot of people with different video drivers, different driver setting, different cooling, CPUs, etc... that seem to have a significant performance impact. So yes there are likely to be some settings that are more optimal for this card.

A score of 180fps however would be just about off the charts (too high) even for the most optimized system for this card.

Maybe the pop-up forced the card out of full screen mode and back into desktop mode (with the 3D scene running in a window). There shouldn't be a significant different in performance, but it does depend on the driver and card. You can play around with this in the Advanced test window for 3D. Check and un-check the "windowed" box.