How to fix I/O blocking on Onda A520-VH-W in Metro Exodus?
Every time I entered a new subway tunnel, the screen would have these periodic micro-pauses, almost like a movie film skipping a frame. The PCIe link on the Onda A520-VH-W was hitting 18-25ms of scheduling latency while handling high-speed NVMe data, leaving the CPU just idling. I tried disabling all my overlays, but the stuttering frequency didn't change a bit—it was a wake-up call that I needed to stop messing with software and look at the I/O priority. I jumped into the BIOS and forced the M.2 slot to Gen 3 mode and updated the chipset drivers. Looking at the RivaTuner frame time graph, the peaks dropped from 42ms down to a smooth 12-16ms. Interestingly, my sequential read speeds dipped by about 5%, but the random read stability improved by 20%, which is what actually matters for gaming. Board temps stayed around 42-48℃. After three hours of testing, the hitches are gone, and memory temps held steady at 58-63℃.
