Chiming in here, because this has been an issue for literal YEARS.
It has absolutely NOTHING to do with external software or outdated/corrupted drivers. It most likely has to do with the fact that DayZ still runs on DirectX11 - as this issue can be almost entirely eliminated by running DayZ on a Vulkan API (I and many others have tested this firsthand).
AMD GPUs have had these issue worse than Nvidia for the last few years, but ever since 1.26, the issue is just as noticeable on Nvidia GPUs as it is AMD.
Most AMD GPU users have had to run specific drivers from May 2020 to get slightly better performance due to changes in how AMD GPUs handle DX11. Reported this one years ago.
I bought an Nvidia 4060 JUST to "fix" these issues back in September of 2024, and it genuinely did fix my frame issues until 1.26 was implemented. But let's get down to specifics about this issue, since I know for a fact I'm not the only one in you lot's ears about it right now: