键位缺口位置支持总线典型用途B Key右侧缺口SATA / PCIe ×2 / USBSATA SSD 或低端 PCIe SSDM Key左侧缺口PCIe ×4高性能 NVMe SSDB+M Key双侧缺口SATA / PCIe ×2(兼容 ...