Hi @Gerspei 

Thanks for posting in our business forum.

Is your computer motherboard capable of 1Gbps? It links to 100Mbps, which is absolutely unusual. If it does not support 1Gbps, it would link to 100Mbps or 10Mbps. Depends on your motherboard NIC.

Cable is rated CAT5e or above?

Cable is under 100 meters? Or poor quality? 3-ft CAT5e, what will be the link speed on the PC?

Run iperf to verify if there is a speed issue or not: How to use Iperf to test the speed of TP-Link switches

Hi @Gerspei 

Thanks for posting in our business forum.

Gerspei wrote

 

Hello @Clive_A , thank you for your prompt response. As the installation performed on CAT6 worked as described in my post, I also tested it with patch cords with identical results.

I tested with 3 PCs: 2 x Dell Desktop and a Lenovo laptop. I also tried connecting it to two switches, 10/100 3Com and TP-Link, and then to the PCs. The results were identical.

I understand that there may be a drop in the conversion from 1Gbps to 100Mbps, but I never thought it could be so high. I'm not sure if it's a problem with this particular switch, so I would like to know if anyone can recommend another model where this issue does not occur.

@Clive_A 

In our lab, 108E is quite solid. I am not sure if this is a hardware issue in your environment. You might RMA or get a different model and test it out. If this continues to drop to 100Mbps, it can rule out the hardware issue from the switch.

Our switch controller, the chipset I mean, might be sensitive to the fluctuation in the electric signal inside the cables. If that's the issue, it is the situation where you either replace the cable or the switch.

Try a different cheap model TL-SG108. It is plug and play. See if it experiences the same issue, if yes, that might be the cabling.

Hi @Gerspei 

Thanks for posting in our business forum.

Gerspei wrote

  @Clive_A 

Perhaps I wasn't clear in explaing the issue; sorry for being repetitive:

 

I currently have a 1 Gbps internet connection with a 1Gbps port connected to a TL-SG108E switch using a 1-meter Cat6 patch cord.

All PCs connected to the TL-SG108E that support 1Gbps are functioning flawlessly.

PCs with a maximum support of 100 Mbps are not receiving speeds close to 100 Mbps. Instead, they are capped at a maximum of 76 Mbps. I have tested it on three different PCs and also changed the patch cord and switch port: same result.

 

When the TL-SG108E switches a 1 Gbps connection from one port to another port at 100 Mbps, it does not provide a speed close to the expected 100 Mbps (e.g., 95 Mbps). Instead, it consistently delivers a mere  76 Mbps (max).

 

Cable length of each patch cord is approximately 1 meter, Cat6 certified.

 

Since most of my network relies on TP-Link products, I am reaching out to the community in the hope that someone may have encountered and resolved this issue or can recommend a switch model where this performance degradation does not occur.

 

Thanks!

So you mean that the PC NIC is 100Mbps, but it is not reaching 100Mbps or so. But at 76Mbps. It is still quite strange.

If it is capped at 76Mbps anyway, try it on the router port and the same CAT6 cable on your router test. Will it still get 76Mbps?

If yes, it is your computer or the cable again. No, that seems to be the switch issue. You can get a different model and test it.

At least I never see this in my career. It might be a single case with hardware issue on it.