82579LM Adapter Settings

[KimoKeala]

I have two exactly the same desktop PCs with identical hardware and Windows 10 Pro OS. Both are connected via Ethernet cables to my router. When I run a speed test, one always reads about 180MBPS download, and the other about 98MBPS download. When I look at the adapter settings, both are set on Auto Negotiation for the Speed and Duplex setting. But the faster desktop's adapter shows a 1G capacity and other shows only 100MBPS capacity. I think this is why the one that reads 98 MBPS download is slower. What is causing this? Is the capacity reading one that is "sensed" by the adapter as opposed to set? Could the length of my Cat-5 cable or its condition be causing these differences?

 

[the nerd 389]

The first place I'd look is at any patch cables you're using. Specifically, if they aren't connecting on one of the pins, it will force the connection into simplex mode. Gigabit ethernet requires full duplex connections. This is the issue more than 90% of the time (for me, at least).

The second place I'd look is at the quality and length of the Cat-5 cables. It's not often that these cause issues, though.

The third place I'd look is at the driver settings for the 82579LM adapter. Try changing the auto-negotiation setting to gigabit. If the connection is dropped, you have an issue with your wiring. If it's not, the issue is simply that the adapter isn't correctly negotiating the connection.

 

[KimoKeala]

The first place I'd look is at any patch cables you're using. Specifically, if they aren't connecting on one of the pins, it will force the connection into simplex mode. Gigabit ethernet requires full duplex connections. This is the issue more than 90% of the time (for me, at least).

The second place I'd look is at the quality and length of the Cat-5 cables. It's not often that these cause issues, though.

The third place I'd look is at the driver settings for the 82579LM adapter. Try changing the auto-negotiation setting to gigabit. If the connection is dropped, you have an issue with your wiring. If it's not, the issue is simply that the adapter isn't correctly negotiating the connection.

 

[KimoKeala]

Thanks for the reply! You are right on the mark!! Using your comments as a guide, I figured it out. I needed both Ethernet and a phone line to that room. Since I did not have a phone line to that room, I used a pair of Cat-5 splitter jacks to get an Ethernet connection and a phone line out of one Cat-5 cable. When I took off the splitters and hooked up the Ethernet cable between my router and my PC, it immediately recognized the 1G connection and my internet download speed went up to what it should have been. So I now know the problem -- I just gotta figure out a way to get a phone line into that room now. I have an idle coax TV line to that room. But that phone line is provided by CenturyLink and don't used coax and a cable modem to provide phone service like Cox does. I have both Cox and Century Link phone service. The CL phone line to that room is provided by my wife's company since she "works from home". Crap, if CL used coax and a phone modem, my problem will be solved. I guess my wife just has to live with half speed internet for now.