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I'm a non-tech with an oddball question -
I have an old Dell Optiplex 755 Desktop PC running Windows XP that I still use for some old stuff. It has an Intel 82566DM-2 Gigabit Network Connection. However, its throughput per speedtest.net is always ~100Mbps down and up and never higher.
Its "Link Speed & Duplex" is set for "Auto-negotiate 1000 Mbps". If I hit "Update driver", it responds that I already have the right one.
The router to which it's wired (by ethernet cable) can handle 1Gbps easily, and the external Verizon FIOS internet speed is 500Mbps.
So - dumb question - why is this PC limited to 100Mbps? What should I check? Could it be the ethernet cable to the router? Should I pour some coffee into the DVD slot?
Thanks.
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Yea, I would be looking at the cable as a possible source for this issue. You need at least CAT5e cables to support Gb speeds.
...S
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Hello glnz,
Thank you for posting in Intel Ethernet Communities.
Aside from the cable that the other forum user suggested. We have a support site for this network card, please open the link below:
https://www.intel.com/content/www/us/en/support/articles/000005644/ethernet-products.html
As per the link, it is also best to coordinate the issue with the manufacturer of the system which is Dell since the network card is onboard/embedded. They are the best team who can further support you with the issue.
If you have questions, please let us know. In case we do not hear from you, we will make a follow up after 3 workings days. Thank you.
Best regards,
Michael L.
Intel® Customer Support
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Also, to everyone - are we sure that this old PC -- a Dell Optiplex 755 -- can actually take a signal faster than 100 Mbps? I do have a recollection that its speedtest.net speed was faster a few years ago, but not 100% sure.
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Also, even if it is a CAT5e cable, if you "split" it to create two LAN connections, the speed will drop to 100mbp/s regardless.
Doc (not an Intel employee or contractor)
[Waiting for Windows 12]
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Hello glnz,
Thank you for the prompt reply. We have generic drivers available for Intel® 82566DM Network Connection in our download site, however I am very sorry to say that there is no driver for your OS which is Windows XP. That is why we have that link to guide our customer's who are using this network card on how get further support and that is via your Computer Manufacturer. They should may have customized drivers and software to enable or alter features, or provide improved operation on your computer.
Here is the support site of Dell OptiPlex 755. Kindly check the drivers and you may also contact their technical support from this link:
https://www.dell.com/support/home/en-my/product-support/product/optiplex-755/drivers
If you have questions, please let us know. In case we do not hear from you, we will make a follow up after 3 workings days. Thank you.
Best regards,
Michael L.
Intel® Customer Support
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Hello glnz,
I hope you're having a wonderful day. I am just checking if you still have clarifications and we are hoping that you are now talking with Dell for further assistance.
If you have questions, please let us know. In case we do not hear from you, we will make a follow up after 3 workings days. Thank you.
Best regards,
Michael L.
Intel® Customer Support
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Hello glnz,
I hope this message finds you well. I am just sending another follow up to check if you still have clarifications. Since we have not heard back from you, I need to close this inquiry.
If you need any additional information, please submit a new question as this thread will no longer be monitored.
Thank you and stay safe.
Best regards,
Michael L.
Intel® Customer Support

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