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I have an external hard drive (a WD 2TB My Book Live) connected to a router (a D-Link DIR-615 running DD-WRT) via ethernet cable. I also have a desktop with a "Realtek PCIe GBE Family Controller" connected to the same router via an ethernet cable.

Whenever I transfer files across the network, speeds are limited to about 11 MB/s. Considering that both the external hard drive and desktop are capable of gigabit speeds, I would have expected a slightly faster transfer rate.

According to Windows 8.1, the adapter on the desktop machine is connected at 100.0 Mbps:

enter image description here

I checked the Device Manager, and "Speed & Duplex" for the adapter is set to "Auto Negotiation". So this is obviously a problem with the router.

I used telnet to connect to the router and check the speed of eth0:

# cat /sys/devices/platform/ag71xx.0/net/eth0/speed

Why is the router operating at a slow speed? Is there anything I can do to make it faster?

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Could be the cable - have you tried another one? – Journeyman Geek Feb 6 '14 at 7:16
up vote 5 down vote accepted

Because DIR-615 is a non-gigabit capable router. It has 4 x 10/100 ports, and 1 x 10/100 WAN port.

Even if your PC, and your NAS can support Gigabit, the weakest link speed will be used.

Check D-Link DIR615 Spec here.

The only way to make it faster, is to get a new router that support gigabit. Or maybe direct-connect your PC to your NAS via ethernet.

share|improve this answer
Blah, can't believe I missed that. Nice catch – Journeyman Geek Feb 6 '14 at 7:28
Hmmm... I better keep my eyes out for an upgrade. – Nathan Osman Feb 7 '14 at 2:14

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