Question Ethernet speed limited to 100 mbps on new motherboard

[barnabasgrand]

Yesterday I installed my new motherboard Asus TUF B650M-e along with new CPU, etc. I noticed my download speed went down drastically. It's because I think my motherboard or something in Windows is now limiting it to 100 mbps. I changed speed and duplex setting to 1 gbps. It was working okay for a few minutes, then my internet lost connection, it came back and it was reset again to 100 mbps. My cable is cat6.

 

[drivinfast247]

New Windows install after motherboard change?

What "Cat6" cable?

 

[faalin]

Installed new motherboard and CPU, did you reinstall windows? At the least did you reinstall all drivers?

 

[bill001g]

You want to always leave the setting on auto. To use other setting you must also change the router and most routers only use auto.

So first we will just assume that your router has gigabit ports.

The speed negotiation is mostly a hardware function so unlikely it is any firmware or driver issues.

These type of problems are almost always a defective cable. The only other option would be some defect in the physical port.

There are massive numbers of fake cables sold. The main fake cable you see are those flat ones. The "cat" number means nothing what is important are the actual certifications like EIA/TIA. You only need cat5e cable to run 1gbit but the cable must be pure copper (no CCA) and must have wire size 22-24 awg. Most those flat cable have wire size 30 or 33 which is much to small to meet the standards to be a true ethernet cable.

Then again even the very best cables can fail. All it takes is one of the wire inside the end plugs to become slightly loose.

I would buy a new quality cable and see if it fixes your problem. It is going to be the cheapest thing because after that you start to consider a defective mother board port which can't really be fixed.