局域网内网络测速工具 IPERF3，下载好后在命令行中执行，分客户端和服务端，先执行服务端命令 ，再执行客户端命令。用了USB2.5G网卡，速度总是上不来，最后才发现要插入USB3.0口，USB2.0速度才350Mbits/sec左右。
服务端：iperf3.exe -s；
客户端：iperf3.exe -c 对方IP -t 10；
C:\Users\Administrator\Desktop\Test\iperf3>iperf3.exe -s
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.2.13, port 61653
[ 5] local 192.168.2.2 port 5201 connected to 192.168.2.13 port 61654
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 39.3 MBytes 330 Mbits/sec
[ 5] 1.00-2.00 sec 41.2 MBytes 346 Mbits/sec
[ 5] 2.00-3.00 sec 41.2 MBytes 346 Mbits/sec
[ 5] 3.00-4.00 sec 41.2 MBytes 346 Mbits/sec
[ 5] 4.00-5.00 sec 41.2 MBytes 345 Mbits/sec
[ 5] 5.00-6.00 sec 41.2 MBytes 345 Mbits/sec
[ 5] 6.00-7.00 sec 41.2 MBytes 345 Mbits/sec
[ 5] 7.00-8.00 sec 41.2 MBytes 345 Mbits/sec
[ 5] 8.00-9.00 sec 41.2 MBytes 346 Mbits/sec
[ 5] 9.00-10.00 sec 41.2 MBytes 345 Mbits/sec
[ 5] 10.00-10.05 sec 2.04 MBytes 344 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-10.05 sec 0.00 Bytes 0.00 bits/sec sender
[ 5] 0.00-10.05 sec 412 MBytes 344 Mbits/sec receiver
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.2.103, port 62305
[ 5] local 192.168.2.2 port 5201 connected to 192.168.2.103 port 62306
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-1.00 sec 108 MBytes 904 Mbits/sec
[ 5] 1.00-2.00 sec 112 MBytes 942 Mbits/sec
[ 5] 2.00-3.00 sec 112 MBytes 942 Mbits/sec
[ 5] 3.00-4.00 sec 112 MBytes 942 Mbits/sec
[ 5] 4.00-5.00 sec 112 MBytes 942 Mbits/sec
[ 5] 5.00-6.00 sec 112 MBytes 942 Mbits/sec
[ 5] 6.00-7.00 sec 112 MBytes 942 Mbits/sec
[ 5] 7.00-8.00 sec 112 MBytes 942 Mbits/sec
[ 5] 8.00-9.00 sec 112 MBytes 942 Mbits/sec
[ 5] 9.00-10.00 sec 112 MBytes 942 Mbits/sec
[ 5] 10.00-10.04 sec 4.79 MBytes 939 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bandwidth
[ 5] 0.00-10.04 sec 0.00 Bytes 0.00 bits/sec sender
[ 5] 0.00-10.04 sec 1.10 GBytes 938 Mbits/sec receiver
Windows 端：右键「此电脑→管理→设备管理器→网络适配器」，找到你的 2.5G 网卡（如 Realtek 2.5G Family Controller）→右键「属性→高级」；
找到「链接速度和双工模式」，确认当前值是2.5 Gbps 全双工（不是 “自动协商”“1 Gbps”“100 Mbps”）；
若显示 “自动协商”，手动改为 “2.5 Gbps 全双工”，重启电脑后再用 IPerf3 测速（自动协商偶尔会识别错误，手动指定更稳定）。