$computer = "LocalHost"
$namespace = "root\CIMV2"
$Tcpip_NI = Get-WmiObject -class Win32_PerfRawData_Tcpip_NetworkInterface -computername $computer -namespace $namespace
$Tcpip_NI | Select BytesReceivedPersec,BytesSentPersec,BytesTotalPersec

在仅使用wmic的cmd行中：

wmic path Win32_PerfRawData_Tcpip_NetworkInterface Get BytesReceivedPersec,BytesTotalPersec