8000Hz (8K) USB Polling Rate Architecture and CPU Interrupt Overhead: Advanced Implementation and Real-World Architecture

[Gabriel Ward]

Alright, real talk on 8K polling—I’ve been pushing a 8000Hz mouse through my setup and the CPU tax is showing up where I least expected. My concern isn’t raw latency, it’s the interrupt plumbing. At 8K you’re looking at 8000 USB events per second feeding straight into the DPC/ISR path, and I’m seeing periodic 0.3-0.5ms DPC latency spikes in LatencyMon that correlate with visible micro-stutter in fast-tick shooters like VALORANT, even with idle cores pinned to my game.

Two questions for anyone who’s actually dug into this at the low level: How are you mitigating interrupt coalescing pressure when the OS can’t batch at these frequencies—any luck with USB Interrupt endpoints using report descriptors, or is it worth moving polling off the main render thread onto a dedicated core with affinity? And more importantly, has anyone benchmarked the actual input-to-photon delta between 4000Hz and 8000Hz in an engine like Unreal or a custom source-modified build, or is the diminishing return just not worth the CPU overhead for competitive play?

"Keychron Q1 Max (Gateron Jupiter Banana) + Artisan Hayate Otsu Mid"

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