Intel Ethernet bottlenecking Internet?

It seems there is a line-speed mismatch between your PC and the modem/router.
This is a software setting on the PC side, so it can have changed by replacing the drivers.

If the modem/router has Gigabit capable ports make sure that the PC is set to Auto-speed, auto-duplex. (The Intel NIC on your motherbaord is also Gigabit capable and auto usually works best for Gigabit.)

If the modem/router is NOT gigabit capable you will have to set the PC to either 100 Mb auto-duplex, 100 Mb/full-duplex or 100 Mb/half-duplex.

You can make/verify these settings in the properties of the network adaptor.

You may have to experiment what works best in your case.
For 10/100 Mb ports the exact behavior of line-speed auto-negotiate is not well-defined and some manufacturers have strange ideas on how to implement it.
(Intel actually does it very well, but consumer-grade modems/routers are notorious for shoddy implementations. This can lead to it working properly with one computer and not working well with another.)

Tonny

Posted 2013-11-07T10:59:00.713

Reputation: 19 919

How do I set my pc to auto speed/auto duplex? – Donald Darma – 2013-11-07T23:28:31.280

That depends on the exact driver and Windows verison. I can't say in general what it would look like on your systems. But you will have to set it in the properties of the network adapter. – Tonny – 2013-11-08T13:28:56.723

I figured it out and it works but every time I start up my computer it doesnt connect. I have to change the value to something else and then back to 100 mbps half duplex for it to get a connection. After that it runs fine. Any ideas? – Donald Darma – 2013-11-09T07:15:49.110

@DonaldDarma That confirms that your modem/router has a weird implementation. It is possible that the modem (in it's web-interface) allows you to set it's idea of speed and duplex for the port onto which the PC connects. In that case set the modem and PC both to matching settings: the highest full-duplex speed supported by both sides. That should fix the problems with reboots. P.S. Just unplugging the PC from the LAN cable and plugging it back in may have the same effect as re-configuring it and it probably quicker to do. – Tonny – 2013-11-09T10:28:20.390

I cant find any software for my modem, is there a way to manually set it? My modem is a surfboard SBG6580. – Donald Darma – 2013-11-09T21:59:13.200

I'm not familiar with that particular type of Surfboard. Usually for Surfboards: If you disconnect it from the ISP and then boot it it will come up in a special config mode. Connect a computer, it will get an ip-address suplied by the Surfboard, and then point a web-browser to the ip-address of the modem (==default gateway of the computer). You can then access the config of the surfboard. Chances are that when you reconnect the Surfboard to the ISP the ISP supplied settings will override your own changes. In that case the ISP tech-support may be able to set it for you. – Tonny – 2013-11-10T14:08:49.490

run iperf between your comp and your laptop, is there a bottleneck there? if indeed you are limited to 10Mb/s on the NIC, you'll see the same limitation to any other device on the network. What is your link rate/duplex on the interface? Ensure you are linked at the same rate as the the port on the switch and are running full duplex. try replacing the cable? defective cables are a very common reason for performance issues, especially when it affects only one device on a network. You might also try a different switch port. – MaQleod – 2013-11-07T11:09:39.107

Can you provide specific information ( in the question itself ) on the ethernet adapter? I suspect this is either one of two things, one you can fix by changing a setting the other you can't without diferent hardware. If you are using a ADSL and/or Cable Modem specific model information is required to help you. – Ramhound – 2013-11-07T13:19:05.993

You don't say whether this is wired or wireless (and Intel makes both). But if wired, I'd suggest you check the cable, as MaQleod says, but more because sometimes people simply grab the wrong (type of) cable too, and it's easy to check. 10Mb speed suggests not having Cat5 cable. – Debra – 2013-11-07T14:23:55.127

Intel Ethernet bottlenecking Internet?

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