One of my computers doesn't seem to want to operate at gigabit speeds.

Viper87227

Viper87227

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I recently said to hell with wireless and wired my apartment with Cat6. My desktop computer next to the router is running fine at 1Gbps. My media center one room over is only running at 100Mbps, and I cannot figure out why.

The motherboard has a Realtek RTL8168D . I have green ethernet enabled... could that be it? Auto disable gigabit is disabled. I tried changing speed & duplex from Auto to 1Gbps, and that didn't change anything. The latest driver is installed. Their ethernet diagnostic utility shows the link speed at 100.

Anything else I can try here? I see no reason why it shouldn't be working.
 
Did you wire the cabling properly?

GigE uses all 8 conductors, and they have to be wired to the proper standard. If you just matched colors on each end, it won't work right.
 
jjeff1 said:
Did you wire the cabling properly?

GigE uses all 8 conductors, and they have to be wired to the proper standard. If you just matched colors on each end, it won't work right.
Click to expand...

By wired my apartment, I meant... I bought a few 100ft Cat6 cables and ran them through the ceiling. So, yeah, everything should be wired properly.
 
Try to use a shorter/more direct cable and see if it links up at a gig if you can. If it does, then maybe trace the line you ran and avoid any electrical interference running near lamps or electrical wiring. If the short cable doesn't help, I would try updating/reinstalling the drivers for the nic. Also, you should set the NIC back to auto and let it determine the speed on it's own.
 
aaronearles said:
Try to use a shorter/more direct cable and see if it links up at a gig if you can. If it does, then maybe trace the line you ran and avoid any electrical interference running near lamps or electrical wiring. If the short cable doesn't help, I would try updating/reinstalling the drivers for the nic. Also, you should set the NIC back to auto and let it determine the speed on it's own.
Click to expand...

There's nothing that could be causing interference. I don't have a shorter cable to test with. It's still a room away, I'd need a good 50ft running it on the floor. I don't want to buy another cable just to test with.

I'll totally uninstall and reinstall the driver and see if that helps.
 
If you wired them through the ceiling are they passing near any fluorescent lighting or any other high voltage electric?
 
Viper87227 said:
There's nothing that could be causing interference. I don't have a shorter cable to test with. It's still a room away, I'd need a good 50ft running it on the floor. I don't want to buy another cable just to test with.

I'll totally uninstall and reinstall the driver and see if that helps.
Click to expand...

Another way to diagnose the wiring is to swap the computers to the other location (meaning putting the computer in question into the location of the other computer, and vice versa). If the other computer (relocated to the trouble spot) drops to 100 Mbps, then you may have a wiring problem (or there is too much wire for a given CAT level). Remember, a lot of cables have relatively high loss, especially with runs more than about 30 to 50 feet. Generally speaking, running more than 50 feet of CAT6 wire can drop the Gigabit Ethernet connection to 100Mbps if the cable is of relatively low quality.
 
Reinstalling drivers did nothing. Could it really be the length of the cable? I ran two cables to two different rooms, and both had some length, but I don't know that a 50ft would be long enough.

Anything that can be done to make the 100ft cable work?

EDIT: The other cable was running to a PS3, so I wasn't worried about gigabit... but I did have an HTPC out there waiting to be hooked up. So I did, and it showed up with a 1 Gbps connection, no problem. I bought two of the exact same cable, so it's obviously capable of doing it. It has to be something on the other computer... or perhaps a bad cable?
 
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100ft is certainly not the issue; you should be able to get gig even at the max length of 100m (~300ft).

if the HTPC got gig, then it's not a wiring or interference issue.
does your motherboard have 2 NICs? try the other one maybe?

jjeff1 said:
Did you wire the cabling properly?

GigE uses all 8 conductors, and they have to be wired to the proper standard. If you just matched colors on each end, it won't work right.
Click to expand...

uhh.. what? you think a NIC and switch can distinguish colors? As long as both ends are wired the same, regardless of what order you put them in, you can get gigabit speeds.
 
j-sta said:
100ft is certainly not the issue; you should be able to get gig even at the max length of 100m (~300ft).

if the HTPC got gig, then it's not a wiring or interference issue.
does your motherboard have 2 NICs? try the other one maybe?
Click to expand...

Nope, just the one.
 
is this on your gaming machine with the Gigabyte?
can you go in to the BIOS and go to SmartLAN within the Integrated Peripherals?
Looks like it has a built-in LAN cable diagnostic of sorts; per the manual, it should display the link speed and estimated length of the cable

Chibo said:
Why not buy a PCI NIC?
Click to expand...

do you replace parts without thoroughly testing the existing parts to verify it is the issue?
 
move the HTPC to your desk and hook it up with the cable that is connected to your PC and see if it connects at 1gbs.
 
Zepher said:
move the HTPC to your desk and hook it up with the cable that is connected to your PC and see if it connects at 1gbs.
Click to expand...

I think he did.. but I guess he should clarify where he hooked up his HTPC. The HTPC was getting gig on the same cable going to your desktop that only gets 100mb, correct?

Viper87227 said:
EDIT: The other cable was running to a PS3, so I wasn't worried about gigabit... but I did have an HTPC out there waiting to be hooked up. So I did, and it showed up with a 1 Gbps connection, no problem. I bought two of the exact same cable, so it's obviously capable of doing it. It has to be something on the other computer... or perhaps a bad cable?
Click to expand...
 
I read that as he had a different HTPC that was tested where the PS3 was and it had gigabit.
Since he mentions that it has to be something with the other computer, it sounds like 2 different HTPC's to me.
 
j-sta said:
do you replace parts without thoroughly testing the existing parts to verify it is the issue?
Click to expand...
Want to make a wager on putting a PCI NIC in it making it work?
(That and I have nothing but ill will against Reaktek NICs)
 
So.. I suppose I should specify. The computer getting 100mbps is the media server sitting in my projector room. I have another HTPC in my living room... that is the one that is getting gb fine. It's on a different cable, but I bought two of the same one for each computer.

I will move the computer that is getting gb speeds into the other room and see how it does... that will at least identify if its the cable or the system.
 
j-sta said:
uhh.. what? you think a NIC and switch can distinguish colors? As long as both ends are wired the same, regardless of what order you put them in, you can get gigabit speeds.
Click to expand...
They can't distinguish colors but they certainly can be affected by a split pair. Even at 100 megabit split pairs can have a disastrous impact on performance. And 100BASE-TX only uses two pairs while 1000BASE-T uses all four.

Another thing to check is whether all the ports on your router actually support gigabit. On the draytek I have here only one of the ports does.
 
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Ok, dragged the HTPC into the other room... shows 1 Gbps. So, that rules out the cable... its something on the computer.
 
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