多个网卡的驱动程序相同 - 性能瓶颈？

I'm using driver e1000e for multiple Intel network cards (Intel EXPI9402PT, based on 82571EB chip). The problem is that when I'm trying to utilize maximum speed (1GB) on more than one interface, speed on each interface starts to drop down.I'm using driver e1000e for multiple Intel netw