How fast should my gigabit ethernet network be?

Cartoonguy wrote:

I just tried a 500mb file and it took 51 seconds to transfer, compared to about 5 seconds to go from my iMac to FW800. That's crazy slow!!

Numbers can be beautiful. I just turned on internet sharing and connected one machine to another. I copied a 500 MB file in about 8 seconds, using the Finder no less.

Cartoonguy wrote:

I just tried a 500mb file and it took 51 seconds to transfer, compared to about 5 seconds to go from my iMac to FW800.

How long is each cable?

Cartoonguy wrote:

The cable is very long. The house is wired in the walls.

Is the firewire cable the same length as the ethernet cable?

Cartoonguy wrote:

Really! Isn't "internet sharing" just for sharing the internet signal? How does it help two macs to communicate with each other?

The Mac sharing the internet acts as an ethernet router. It is just a quick an easy way to connect two machines without having to disconnect one and setup manual IPs and all that jazz.

The cable is very long. The house is wired in the walls.

Did you ever try connecting two Macs directly with one cable? It doesn't mean anything is someone just wired the building. Did anyone ever bring in a network meter and check it for connectivity? On modern Macs you can plug two machines together with one cable and it will automatically switch to crossover mode. I have no idea if that will happen correctly when going through cables and jacks in your walls. Also, you can run System Preference > Network > Ethernet > something and actually see what your link speeds are. Does it actually say gigabit?

You mentioned Telus. Does Mike Holmes do networking? I think that's what you need.

As far as I can tell ethernet does fall back to 1/10th of the speed on marginal connections. Here is some information:

Fallback speed - http://superuser.com/questions/549004/what-happens-when-gigabit-switches-are-con nected-over-an-old-cat5-cable

Technology - http://www.reddit.com/r/askscience/comments/1py4gk/

Cartoonguy wrote:

Yes. Check earlier in the discussion. That was one of the first things I did. It was faster, but still not nearly as fast as FW800. The 820GB file took 11 seconds to go to FW and 18 to go to directly connected ethernet with a Cat5e cable.

That sounds reasonable.

Through my house ethernet network, same file takes about 50 seconds, so much slower again.

Then you know where the problem is 🙂

I know a guy who is an IT and networking professional and he offerred to come by and check things out so I will report back on his findings in case it helps anyone else with problems like I am having. Fingers crossed he discovers the issue.

Does he have a meter? That is really the only reliable way to diagnose things.

Check for network errors.

Where Ipkts=Input Packets Ierrs=Input errors Opkts=Output packetts Oerrs=Output Errors Coll= Colisions

en0 is the ethernet link. Notice the three en0 are all the same, basically. Notice my error rate is zero.

Notice i xxxxxxxxxxx'd out personal information -- the MAC addresses ( ethernet hardware address ).

terminal app.

mac $ netstat -i -n
Name  Mtu   Network       Address            Ipkts Ierrs    Opkts Oerrs  Coll
lo0   16384 <Link#1>                         41702     0    41702     0     0
lo0   16384 127           127.0.0.1          41702     -    41702     -     -
lo0   16384 ::1/128     ::1                  41702     -    41702     -     -
lo0   16384 fe80::1%lo0 fe80::1              41702     -    41702     -     -
gif0* 1280  <Link#2>                             0     0        0     0     0
stf0* 1280  <Link#3>                             0     0        0     0     0
en0   1500  <Link#4>    00:xxxxxxxxxxxxxx    13428     0    13215     0     0
en0   1500  fe80:xxxxxx fe80xxxxxxxxxxxxx    13428     -    13215     -     -
en0   1500  192.168.0     192.168.0.10       13428     -    13215     -     -
fw0   2030  <Link#5>    00:03:93:ff:fe:96:13:1c        0     0        0     0     0
mac $ 


I used the ifconfig command to find out the mtu size mine is 1500 for en0.  This is good.  It is about the largest size allowed.

mac $  ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
    inet 127.0.0.1 netmask 0xff000000 
    inet6 xxxxxxxxxxx 
    inet6 xxxxxxxx%lo0 prefixlen 64 scopeid 0x1 
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    inet6 xxxxxxxxxxxxxxxxxxxxx%en0 prefixlen 64 scopeid 0x4 
    inet 192.168.0.10 netmask 0xffffff00 broadcast 192.168.0.255
    ether xxxxxxxxxxxxxxxxxx
    media: autoselect (100baseTX <full-duplex>) status: active
    supported media: none autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,hw-loopback> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,hw-loopback>
fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 2030
    lladdr xxxxxxxxxxxxxxxxxxxxxxxxx 
    media: autoselect <full-duplex> status: inactive
    supported media: autoselect <full-duplex>

I forgot to mention that my test was on a FireWire 400 cable.

With the ethernet connection in my place, I tested sending a 901.9MB files would just take 14 seconds to other Mac via 4 switches over a 40M CAT5e cable. It took 5 seconds more than my previous test.

You said that your direct ethernet connection takes 18 seconds, which is indeed a bit slow. But we don't know if it is the sender's or receiver's problem.

Ask your IT friend to bring his laptop to do the test with your iMacs and MBP. We don't know if it is one of your iMacs or your MBP doing the culprit. You have to do cross-checks.

If possible, move your iMac for direct ethernet test. It is not too heavy.

100 MB in 26 seconds is slow even for a 100 M bit per second connection.

I suspect that your network has fallen back to 100 M bit per second and in addition you either have too many other processes running or some other problem.

Do you have virus checking enabled?