Great topic, and you’re touching on a distinction that most people get backwards. DPC latency isn’t really “NVIDIA vs Windows kernel” as a rivalry — it’s about which components in your system are dumping the most Deferred Procedure Call work onto the CPU during gameplay. NVIDIA’s display and audio drivers (nvlddmkm.sys for the GPU, and High Definition Audio for HDMI/DisplayPort audio) are famously the usual suspects for spikes, because the driver has to service interrupts every time it needs to submit a frame or handle audio buffer flushes. But here’s the nuance: the kernel itself isn’t the enemy — it’s the scheduler and how it prioritizes these DPCs. If you’re seeing sustained latency in LatencyMon, the graph will tell you which .sys file is hogging the CPU. Usually it’s nvlddmkm.sys sitting at 20-40ms during heavy GPU loads, which means your driver isn’t being throttled properly or you’ve got a background process fighting it.
Practically, before you start tweaking kernel timers, isolate the variable. Disable your NVIDIA HDIAudio device in Device Manager if you’re not using speaker audio over your monitor — that alone kills a massive source of periodic DPCs. Then make sure you’re on a recent Game Ready Driver, but also test an older stable build, because NVIDIA has shipped drivers with genuinely bad DPC behavior in the past. Turn off MPO (Multi-Plane Overlay) in the registry — this is the single highest-impact change for most people and directly reduces driver/kernel interaction overhead. For the kernel side, make sure you’re using the highest performance power plan, disable CPU C-states (C1E especially) and SpeedStep via BIOS, and confirm Windows Timer Resolution is at 0.5ms (the timerses or PowerTune approach) so your interrupts aren’t quantized into larger buckets. If you post your LatencyMon screenshots with the top offenders
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