Theoretical speed on different speed ethernet

Hi guys, I just got my book live 3TB yesterday and I am very, very happy with it. Actually I have got a my book studio edition II 4TB, but this time I want to put all my media files on the MBL to serve it as a media server so my TV/HD Player/iPad/Other PC can play the video, music and photos easily, without turning on my computer.

I just want to check the network speed between the computer and MBL on different ethernet: Fast Ethernet i.e. 100 Mbit/s and Gigabit Ethernet i.e. 1000 Mbit/s. I have confirmed that my computer network port on the MB is gigabit version, and I just got a Cisco gigabit switch. Here is my result tested by copying files:

Gigabit Ethernet - 40MB/s max., normally 30-40MB/s

Fast Ethernet - 20MB/s

I have to mentione that yesterday the ethernet cable is CAT5E. I know it is said CAT5E is enough for gigabit transmission, but today I will receive CAT6 cable so I can test again.

I am doing this because I just tested a small part of my home network, if the faster solution is good, I have to replace my main router into a gigabit version altogether.

Of course, if it doesn’t improve too much, I will just live with what I have now. Any comment is appreciated. Thanks!


 Fast Ethernet - 20MB/s


Fast Ethernet Max is 11-12 MB/sec, which equals roughly 88 to 96 Megabits per second.  Fast ethernet tops out at 100 Megabits per second, so 20 MegaBYTES per second is impossible.

I think your testing method is not correct.

And no, you won’t need to replace your main router.   My router is 100 megabit only, but I attach a Gigabit Ethernet switch to it, and plug all my devices into the switch instead of the router.

Thanks for the reply anyway.

I tested the ‘fast ethernet’ in company, and I did  use this giga switch, but I think the ethernet controller for the computer is 100MB version. Well, it performs not as good as gigabit port, but better than fast ethernet.

When I was back home, I can confirm my computer is gigabit port hence the conclusion.

Since the topoloty is a bit complicated. I have tested with another computer which plugs into the router, it is 10MB/s speed.

anyway I am glad got the comment so I have some idea about the speed both theoratically and in real world.