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Checking Google, 100mbps (Fast Ethernet, wired) is ~12MiB/s but in reality, transferring a file over the network (home LAN) is only ~1.5MiB/s. Why might that be?
I am on Ubuntu 11.10 transferring to Windows 7 (the other direction, copy, gives a similar speed).
Jiew Meng
Posted 2011-12-18T03:12:41.237
Reputation: 1 263
3
Use a tool like IPerf to really see what your TCP throughput is with a well-optimized TCP app. IPerf will also tell you what your default TCP window size is, which might be telling.
Check to make sure all of your Ethernet cables are properly wired. Many people (and cable testers) check for pinout correctness without checking to make sure the conductors from each pin is twisted together with the conductor from the correct paired pin (Hint: 1&2, 3&6).
Spiff
Posted 2011-12-18T03:12:41.237
Reputation: 84 656
2
It's possibly due to interface errors, so check for that (specifically for speed/duplex).
It could also be that the router/switch/hub doesn't have enough juice, so try a crossover connection just to make sure its not that.
alexus
Posted 2011-12-18T03:12:41.237
Reputation: 2 484
how do I check for interface errors? I am using Ubuntu, the computer I an transfering to is Windows 7 – Jiew Meng – 2011-12-18T12:15:52.043
ifconfig will tell you if you have any collisions – alexus – 2011-12-19T16:14:06.210
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The bottleneck is probably disk I/O, or something other than the ethernet. The something could be the processor, latency, the modem, the network card, the other network card, or evne something that is more system specific.
soandos
Posted 2011-12-18T03:12:41.237
Reputation: 22 744
Just checked again, disk write is ~100MB/s locally – Jiew Meng – 2011-12-18T04:08:56.673
"or something other" is extremely vague.. Could you expand more? – Simon Sheehan – 2011-12-18T04:39:49.790
@SimonSheehan done. – soandos – 2011-12-18T05:09:27.237
2I still find it extremely vague as you don't really provide any way to help speed it up or to find why. – Simon Sheehan – 2011-12-18T13:34:30.647
How exactly are you measuring? How are the two machines connected to each other? (Through what other device(s)?) – David Schwartz – 2011-12-18T05:28:26.200
1Other things to consider that would affect speed, the CAT rating of the cables and anti-virus. When I switched from CAT5 to 5e to 6, each step I got a speed increase. When I rerouted my cables away from power cables the speed was more consistently fast. When I disabled my AV on Windows, that helped speed the transfer. Using SSDs, helps network transfer. Getting the max speed out of your network speed is still kind of voodoo, you almost have to try different things. – Scott McClenning – 2011-12-18T07:22:48.570
@DavidSchwartz, computers are connected by a fast ethernet switch, which is connected to a router/modem for internet access. A computer is connected through a powerline device, but I tried transferring between 2 "non-powerline" device, resulting in similar speeds – Jiew Meng – 2011-12-18T12:13:38.187
@ScottMcClenning, maybe its because my switch is close to wires ... hmmm .... – Jiew Meng – 2011-12-18T12:14:31.577
@JiewMeng, I’m experiencing something similar, but have more detailed information and test results. Do you mind if I hijack your question in hopes of us getting an answer? – Synetech – 2013-09-29T01:45:19.483
@Synetech, Fine with me :) not sure if its post another qn tho – Jiew Meng – 2013-09-29T03:08:04.627