Dell Latitude 5521 Ethernet Adapter (14) I219-LM -- slow Ethernet speed

[Week]

Intel (14) I219-LM Ethernet controller on Dell Latitude 5521.

Newest Ethernet driver 12.19.2.45 (2022-01-30) installed.

Windows 11 Pro.

Two ISP:

ISP1 - 1 Gbits;

ISP2 - 1 Gbits.

While connected to ISP1, Download speed <600 Mbits, while several other laptops (non-Dell) show ~940 Mbits Download speed.

The same Dell Latitude 5521 connected to ISP2 shows download speed ~940 Mbits.

This is definitely an Intel (14) I219-LM Ethernet Controller Driver issue. Different drivers (Dell connected to ISP1) give very different results: newest driver - up to 600 Mbits, older up to 840 Mbits. Or, perhaps this is Ethernet driver's compatibility issue with other installed driver software.

When I bought this new Dell Latitude 5521 with preinstalled Windows 11 Pro on February, it was showing no more than 600Mbits Ethernet speed on ISP1 few months.
And only after my long working hours by changing driver combinations, I managed to achieve that the Ethernet speed finally reached 940 Mbits with the factory-installed Gen3 SSD.
Unfortunately, I didn't document my work and now I can't exactly recreate the steps it took to achieve the desired result. 

Now I've reinstalled Windows 11 Pro and Dell has Ethernet speed only up to 600 Mbits again when connected to ISP1.

Please help with this I219-LM Driver issue.

[Zigfreid_Intel]

Hello Week,

Thank you for posting on Intel Ethernet Communities. 

Firstly we'd like to set your expectations for the Original Equipment Manufacturer(OEM) for your Intel I219-LM Ethernet controller that you are using, we have limited support and it would be best if you can also get in touch with the manufacturer for further support since they have customized drivers, firmware and software to enable or alter features on your card. They are in best position where you can seek assistance so you don’t lose features or customizations of the Ethernet controller. But don't worry as we will still provide our best effort support to help you resolve the issue. 

Since you have mentioned that you are not getting the correct advertised speed on your device please try using our recommendations on our supported article "Intel® Ethernet Connection I219-V Unable to Reach Gigabit Speed" on the link below. 

https://www.intel.com/content/www/us/en/support/articles/000058667/ethernet-products/gigabit-ethernet-controllers-up-to-2-5gbe.html#:~:text=Double%2Dcheck%20if%20the%20established,comes%20with%20full%20Gigabit%20support.

Also if you will be needing to re-install your drivers we would advise to do first a clean state driver then you can also try using our drivers. However just to advise, our drivers are only generic and if it would still not work please try using the drivers provided by your OEM (Dell). 

Please use the links below as reference;

Clean Driver Installation Guide for Intel® Ethernet Connections

https://www.intel.com/content/www/us/en/support/articles/000058304/ethernet-products.html

Intel® Ethernet Adapter Complete Driver Pack

https://www.intel.com/content/www/us/en/download/15084/intel-ethernet-adapter-complete-driver-pack.html?erpm_id=1901020_ts1649036869798&erpm_id=1901020_ts1649036873159

If you have questions or other clarifications please let us know so we can help you further.

Awaiting to hear from you soon, should there be no response from you, I’ll make sure to reach out after 3 business days. Thank you and have a nice day!

Best regards,

Zigfreid I.

Intel® Customer Support

[Week]

Hello

with the help of Dell Support, we managed to determine that the slowdown of Ethernet speed when connected to ISP1 is caused by Acronis Cyber Protection Home Office. Why this is so and why Acronis does not slow down Ethernet speed when connected to ISP2 - we do not know yet. We are looking for solutions to the problem with Acronis Support.

[Zigfreid_Intel]

Hello Week, 

Since you have already been advised by the manufacturer (Dell) that the issue that you are experiencing is with your security software (Acronis Cyber Protection) can we ask if you have further concerns or can we already ask if we can close the thread?  

Awaiting to hear from you soon, should there be no response from you, I’ll make sure to reach out after 3 business days. Thank you and have a nice day!

Best regards,

Zigfreid I.

Intel® Customer Support

[Week]

Yes the thread can be closed. Thank you.

[Zigfreid_Intel]

Hello Week, 

Thank you very much for advising. We will now close this request and for future concerns just feel free to post a new question as this thread will no longer be monitored. Thank you and have a nice day!

Best regards,

Zigfreid I.

Intel® Customer Support