internet adapter speed changed 1gbp > 100mbp

[Isoz]

so i have a gigabyte network cable with my builtin network card in my pc and its been fine until recently, i noticed in the ethernet status page under speed itstead of showing as 1gb is now showing at 100mbps, for the last 2 months ive been having trouble with my ISP and reciveing crappy speeds but i now think its caused by my lan card/ cable? however i dont know how to fix it.

anyone have any ideas ?

• OS - windows 10.
• cable - CAT6
• motherboard - Maximus VII Hero ATX Motherboard

[Tradewind]

What's the other end of the network cable plugged into? A link can only go as fast as its highest connection. If the device at the other end is negotiating its link speed at 100Mbps, then that's likely the problem. What is your ISP providing in terms of throughput for your service?

You can force it to use 1Gbps through the advanced options for the NIC (right click start menu > control panel > network and sharing center > change adapter settings > right click LAN adapter > properties > advanced > Speed & Duplex) but chances are it's set to Auto Negotiation, which it should be 99.9% of the time, and this doesn't matter at all. Plus if you set it to 1Gbps while the other end is 100Mbps, you're going to run into some pretty serious problems.

[Biernot]

do you have an internet connection that is faster than 100MBit? If not, then the change from 1GBit to 100MBit in your network connection does not impede your internet.

But the sudden change in the network connection may hint at underlying hardware problems. Meaning, that at least one device in your connection chain seems to have issues. I don't know your exact network setup, but typical would be something like:
PC - Switch - Router - Modem - ISP
where some of these functions may be combined in one device (e.g. router with included switch, or router with included modem).

So if you have a switch, try plugging your pc directly into the router/modem and see if that changes something.

[Isoz]

my connection is plugged directly into the modem. i should be on a 200mb connection but im getting less than 10mb atm ( which is a ongoing problem im having with my ISP ). i think thats where the problem is comming from but its hard to prove, ive had a engineer out at my house to look at the problem and they blame it on the tesolation in the area during peak times even even though it happens without of peak time hours. and sometimes my connection just dies out completely

[Biernot]

my connection is plugged directly into the modem. i should be on a 200mb connection but im getting less than 10mb atm ( which is a ongoing problem im having with my ISP ). i think thats where the problem is comming from but its hard to prove, ive had a engineer out at my house to look at the problem and they blame it on the tesolation in the area during peak times even even though it happens without of peak time hours. and sometimes my connection just dies out completely

1. If you are only getting 10MBit or less actual bandwidth, then it is either your ISP or the modem.
2. If you are only getting a 100MBit lan connection to your modem, then it is either the network port on your pc or the modem.

-> Most likely a faulty modem (but other causes are not off the table).