Gigabit Ethernet speed drops to 11MB instead of 60 MB when copying files between PCs

[DanceswithUnix]

Does your switch have any status lights on it?

Gigabit ports are a bit of a bodge. They can negotiate from 1GBit down to 10Mbit. If the switch has decided one of the ports needs to be downgraded, then they will re-negotiate to a lower speed.

Most switches have an LED on each port that says whether it has negotiated a gigabit connection or not. If you have that, it is worth checking you haven't dropped wire speed.

[holygamer]

There's no reason why it should lower the speed as there's nothing else going on using the bandwidth or anything.

I get the proper speed for a couple of weeks then the speed drops to 10 Mbit permanently unless I disconnect and reconnect the cable from both the switch and the satellite box.

When the speed drops the light indicator shows it's at 10 Mbit speeds.

I don't know why they make ethernet cables with clicking mechanism's but when it's clicked into place inside the switch, there's still a bit of give to it, you can pull it out slightly even when it's still clicked in. I think that may be what's happening but I'm not sure as the boxes are on a shelf out of the way and nothing is moving the cables.

[watercooled]

Ah so it is negotiating down. What length and brand of cable are you using?

It's not uncommon to have problems with cheap no-name cables, but it's less common with shorter ones. However if there's something up with the fit of the connector, that could cause it too.

[holygamer]

I've got a TP-Link TL-SG1016D 16-Port Gigabit Desktop Switch and I'm using Duronic 2m CAT6 FTP cables everywhere.

[watercooled]

Oh yeah you did say that earlier.

Have you tried another port on the switch, and/or another cable if you have a spare?

The sat box could also be doing something strange itself.

[holygamer]

Don't have any other cables. Using different ports made no difference. I suppose I could buy another cable. What cable would you suggest - preferably looking for something that when it clicks into place there's no give in it

[watercooled]

It may not be the cable, hence why I suggested just giving a spare one a try if possible (e.g swapping with one connected to PC). It's not unusual to have a small amount of play in the connector.

Since presumably nothing else connected to the switch with similar cables, as I said it could be something up with the NIC on the sat box.

[DanceswithUnix]

There's no reason why it should lower the speed as there's nothing else going on using the bandwidth or anything.

Link speed doesn't negotiate down because of congestion, but because one end or the other detects errors on the line and decides that 100M or 10M would be a safer bet than 1G. Sounds like you are dropping to 100Mbit speeds.

And that is where it gets messy. It could be the cable, swapping with another can see if the fault follows the cable. It could be that particular port on the switch has damage due to static or something. It could be that the PSU on the switch is getting iffy. It could be the satellite box has a slight problem (worth googling for that perhaps) to see if it is a common fault.

[holygamer]

Switch and cables were brand new a month ago. I'll try buying a different cable. Any suggestions?

[DanceswithUnix]

Not really, I usually just buy whatever is cheap. Cat5e should be fine on a short run. Probably whatever you can find to avoid paying P&P, I think even our local pound shop stocks them these days.

[psi]

TP-Link should have a winpcap based homeplug speed monitor that tells you the actual line speed and not the nic to plug link speed which will show as 1gbps/100mbps, not the actual link speed over your mains connection

[GeorgeStorm]

Have you tried swapping the cables between the storage and the sat box to see if the issue remains?