Driver-related Slow Download speeds on Windows?

[cj99694]

Testing with three separate clients, all with Intel based adapters, all of these only cap out at ~400 Mbps download, whereas iPhones and iPads all reach ~800 Mbps download on the same exact AP. The Intel adapters will also sometimes test up to 800 Mbps upload, but will still never break 400 Mbps download on Windows. However, when booting Linux on all of these machines, they reach the expected 700-800 Mbps. So I believe there is a Windows driver issue limiting download throughput to half of the expected rate.

Here is some more information.

- Client adapters are Intel AX200, AX210, and Killer AX1650s

- Tests were conducted using Windows 10, 11 and Ubuntu 22.04.3

- APs tested are Ubiquiti U7 Pro and UDM.

- The PHY link speeds are 1200 Mbps when clients are connected to the U7 Pro.

- Regardless of AP, speeds always cap out at around 400 on Windows

- This only happens with Intel wireless adapters

- I have tried fresh Windows install, and downloading the latest drivers (23.20.0 for AX200/210 and 35.23.1292 for AX1650s)

- Even on 6GHz, with PHY rates of 2400, I should be getting near gigabit. Instead, I still get limited to 400.

Is anyone able to reproduce this? And anyone at Intel, is this something you guys are aware of>

[JayB_Intel]

Hello cj99694,

Thank you for posting in the Intel® Communities Support.

Please be informed that network performance will vary based on the configuration of each system connecting to the network. However, I would like to suggest a few checks for us to see if we can have your concern addressed.

1. Make sure you are using the latest wireless drivers for your specific system. You can visit your system manufacturer's website (recommended) or use the Intel generic drivers available in our download center.
2. Use the recommended settings - https://www.intel.com/content/www/us/en/support/articles/000005585/wireless/legacy-intel-wireless-products.html for your wireless adapter. You can also visit Recommended Settings for 802.11ac Connectivity - https://www.intel.com/content/www/us/en/support/articles/000024678/wireless.html and Recommended Settings for 802.11ax Connectivity. - https://www.intel.com/content/www/us/en/support/articles/000057574/wireless.html
3. Test the different bands available (2.GHz, 5GHz)
4. Verify that your whole system configuration is compatible and supported (If you are using an AC router with an AX card you may not be able to achieve all the features available for AX connectivity). 
5. Check with your router/modem manufacturer for firmware updates.
6. Contact the service provider for more recommendations to improve the internet speed.

Best regards,

Jay B.

[cj99694]

Hello,

1. Drivers are up to date. I have tested with the latest generic driver and also with the latest available from the respective manufacturers. 

2. The adapters are set to the recommended AX settings.

3. This is tested with both 5GHz and 6GHz. 6GHz also refused to break ~400 Mbps, despite being far less congested.

4. As mentioned, the AP that I have tested with is the Ubiquiti U7 Pro, which is fully AX compatible.

5. The AP is completely up to date.

6. This is not an issue with the internet provider, other non-Intel devices reach the expected speeds reliably.

I do realize that there is a lot of variability with WiFi, but this is a very reproducible issue for me and is isolated to Intel adapters only.

Would you have any insight on where the problem would be? I'm fairly confident that the issue lies with the Intel adapters since non-Intel devices reach the expected speeds. However I guess there is the possibility the AP has compatibility issues with Intel adapters? Please let me know your thoughts on this, and whether I need to take this issue up with Ubiquiti too? Thanks!

[JayB_Intel]

Hello cj99694,

Thank you for the response. Since it is affecting multiple devices, adapters and APs although there a multiple factors that we need to consider to identify the cause. It is highly unlikely that different adapters are affected (AX series and Killer) with different drivers. different software packaging and microcode are having the same results with different tested APs (UMD and Ubiquiti), unless it is really the case.

However, we are willing to look into your concern to see how we can move forward with your concern. I would like to request to download the Intel SSU as this can help us with the situation. Please note to provide system scans using all OS (Win10, Win11 and Ubuntu 22.04.3). Please see links below:

For Windows: https://www.intel.com/content/www/us/en/download/18377/25293/intel-system-support-utility-for-windows.html?v=t

For Linux: https://www.intel.com/content/www/us/en/download/18895/26735/intel-system-support-utility-for-the-linux-operating-system.html

Best regards,

Jay B.

[cj99694]

Hi Jay,

I have collected as many SSU files as I could. The Ubuntu 22.04.3 system was upgraded to Kubuntu 23.10 recently, so that is included instead of Ubuntu 22.04.3. There is also another Lenovo laptop with an AX200 that I can eventually get an SSU file from within a few days.

I have done some extra testing and I hope this information will help you in diagnosing the issue.

I have noticed that the Intel adapters will sometimes run full speed (800+ Mbps) immediately after Windows starts, then within ~10 minutes of uptime, the download speeds will start capping at 400 Mbps. Here are some speedtests demonstrating this on my AX210 system:

Here is the speedtest ran within a few minutes of the system starting up and connecting to the WiFi network:

After about 10 minutes of uptime of the system, I ran another speedtest:

 

Notice how the download speed is now capped to about half of what it was 20 minutes ago.

And to demonstrate that the exact WiFi network is capable of higher speeds, here is what my iPhone always tests at:

So it seems that the Intel adapters are definitely capable of more than 400 Mbps, but it appears some sort of bug is limiting it to half download.

Let me know if you need any more support files or information. Thank you for looking into this.

[JayB_Intel]

Hello cj99694,

Thank you for sharing your findings with us. It appears that something is triggering the speed to go down from around 800 to 400~Mbps. However, we will do further research and investigation on this matter and post the response on this thread once available. Thank you.

Best regards,

Jay B.

[JayB_Intel]

Hello cj99694,

I hope you are doing well. I have sent you an email. Kindly check your inbox. Thank you.

Best regards,

Jay B.

[cj99694]

Hello,

I am just confirming that I have received the email. I will gather the requested information and get it sent over. Thanks for the follow up. 

[VonM_Intel]

Hi, cj99694.

I appreciate your confirmation. I received your email about the requested information that we're asking. We will do further research on this matter and post the response on this thread once available.

Best Regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hi, cj99694.

Thank you for patiently waiting. Kindly be informed that we have sent you a private email regarding our last email conversation.

Best Regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hi, cj99694.

I already received your email regarding the issue. Please be guided that at this rate we will need to do further research on this matter and post the response on this thread once available.

Best Regards,

Von M.

Intel Customer Support Technician

[VonM_Intel]

Hi, cj99694.

Thank you for your patience. Please note that we have emailed you regarding this thread post, as the email contains private and confidential information that cannot be posted here.

Best Regards,

Von M.

Intel Customer Support Technician