如下：
Jul 26 03:42:53 kernel: ixgbe 0000:01:00.1: PCI Express bandwidth of 32GT/s available
Jul 26 03:42:53 kernel: ixgbe 0000:01:00.1: (Speed:5.0GT/s, Width: x8, Encoding Loss:20%)
5*8b/10b*8 = 32 GT/s 有效, 20%无效