I recently built a system with an RTX 5070 Ti ROG Strix, Ryzen 7 9800X3D, TUF GAMING B850-PLUS WIFI motherboard, and 32 GB of RAM. Since the build was completed, I've experienced persistent micro-stuttering and unusually poor 0.1% lows, with games occasionally dropping to around 20–30 FPS. LatencyMon shows frequent spikes from nvlddmkm.sys, even when the computer is idle, and opening a window or folder can cause extremely high DPC latency. The latency disappears before NVIDIA drivers are installed, but DDU clean installs, older driver versions, disabling C-states, Memory Integrity, HAGS, Realtek networking, Wi-Fi, Bluetooth, core parking, and changing PCIe from Gen 5 to Gen 4 have not helped. What else should I check or try?
2 Answers
It may be worth undoing the BIOS and Windows tweaks for now and returning the system to its defaults. Changing several settings at once can introduce a second problem and makes it much harder to identify the original cause. Test with a mostly stock configuration before making more changes.
Check the power supply model and capacity, then monitor CPU and GPU temperatures under load. Pay particular attention to the GPU hotspot, VRAM temperature, and motherboard VRM temperatures. It could also be useful to test a mild undervolt on the CPU and GPU. For the driver, try a minimal installation using a clean NVIDIA driver installer so unnecessary components are excluded.
I’ll check the PSU and all of those temperatures, then try a minimal driver install after returning the other settings to default.

That makes sense. I’ll restore the settings and test each change individually instead of keeping everything disabled.