How to fix PCIe bandwidth stuttering on Maxsun B850ITX WIFI ICE?
Driving through the neon streets was a mess because of these tiny tearing lines across the center of the screen—it was driving me crazy. Because the Maxsun B850ITX WIFI ICE is so compact, the PCIe 4.0 lanes were fighting for resources between the GPU and the NVMe drive, causing VRAM transfer latency to swing wildly between 15-28 ms. I tried enabling Low Latency mode in the drivers, but that was just a band-aid; the tearing stayed. I went into the BIOS and forced the second M.2 slot to Gen3 mode and set the GPU slot priority to 'Highest'. Looking at the RTSS frame time graph, the jagged spikes flattened out, and frame times locked in at 11-14 ms. I did have a moment of panic when my second drive disappeared after the change, but reconfiguring the boot order fixed it. The chipset temp stayed around 55-62℃. Now the tearing is completely gone, and the ride is smooth.