You didn't mention it, but is this an NVMe SSD? Is it connected to a PCIe channel that is direct to CPU, and not through the chipset? AMD tends to have CPU direct PCIe channels on the motherboard, but many Intel motherboards use chipset PCIe channels for SSD's. Motherboard manual should allow you to confirm which you are connected to.
Also doublecheck that that the host windows driver is not the Microsoft default NVMe driver but the SSD maker specific one. There's a known write performance bug in the Microsoft generic NVMe driver that slows it down. Worst case, you can force the driver to use the Intel generic NVMe driver which should improve the write speed.