Wifi speed when on screen share/Miracast

[idata]

I recently purchased an HP Spectre that has an intel AC8265 and am having a problem when using the Miracast function.

When I connect to a TV, the wifi speed slows to a crawl. I am able to connect an old Dell XPS18 that has an AC7260 as well as a Note5 and with both of these devices, when i connect, I am able to get the full speed from the wifi (150Mbs)

I tried updating the driver to the current 19.50.1.5 version, but got the same results. Before i connect and after i release the Miracast connection, the laptop is able to get the max wifi speed.

Has anyone else run into this? I should note that I am running the out of the box image on my laptop and am considering wiping and doing a clean install from windows. I'm not sure if maybe there's some option set in the factory image that may cause this.

I am running Windows 10 Creator's update

Thanks in advance.

[idata]

Hello mb2k,

We understand that whenever you enable screen sharing via Miracast* your connection rate drops severely.In order to better assist you we would first like to get a better look at your system.Please download the https://downloadcenter.intel.com/download/25293/Intel-System-Support-Utility Intel® System Support Utility. You will then need to use this application to scan your system and generate two separate reports: one while sharing your screen, and one with Miracast* disabled. You can then share these files with us by switching over to the "advanced editor" while replying.We look forward to hearing back from you.Best regards,Carlos A.

[idata]

Thanks Carlos.

I've updated the Support Request # 02745816 with SSU results with Miracast on and off.

I tried to update the Environment Details but it wouldn't let me.

[idata]

mb2k,

We have reviewed your logs, but were unable to identify any issues.There was actually something a bit odd, when Miracast* is enabled your connection rate (data transfer speed between your laptop and your router) actually improves:- Connection rate w/ Miracast* enabled = 866.7 Mbps.- Connection rate w/o Miracast* = 780 Mbps.Normally we would expect the opposite -a slight drop in your connection as you're sharing wireless bandwidth between your internet and your screen casting. Even if there was a mix-up when naming your logs, 780 Mbps is a strong connection rate that should allow you to maintain a more than fair internet download speed.In this case it's possible that the issue could be coming from somewhere other than your wireless adapter, something else causing your system to get hung up.Reinstalling your OS is one troubleshooting route, but our main recommendation would be to engage your http://www.intel.com/content/www/us/en/support/topics/OEMs.html computer manufacturer for further Miracast* or hardware troubleshooting.Best regards,Carlos A.

[idata]

Thanks, I will contact HP support.

Something I just noticed though, I was testing Wifi speed with fast.com and noticed it didn't breakdown download/upload speed so I tried a few others like speedtest.net and Bing's speedtest and found that while the download speed is <3Mbs, the upload is near max at around 145Mbs. So somehow the Miracast is killing my download speed but not my upload speed.

Thanks again.

[idata]

mb2k,

This is highly unusual to say the least. If there is anything else we may help you with, fell free to contact us again.Best regards,Carlos A.

[idata]

After some more troubleshooting, I think the culprit is Windows Creators Update.

I factory reset my laptop, installed all updates and the latest drivers, and was able to maintain 150Mbs on a Miracast connection.

I then installed WCU using the Upgrade Assistant and after that installation was complete, the laptop went back to <5Mbs down / 150Mbs up when on a Miracast connection.

So the issue seems to be with the WCU. I've provided HP with this information and have submitted the issue to the windows community.

Is there anyway for someone from Intel to try duplicating this matter by using the same AC 8265 on a WCU machine?

[idata]

Hello mb2k,

I'm not sure if we're able to escalate this issue since we don't provide Miracast* support. But I will definitely bring this up to our engineering team to see what we can do to look into this from our end.If we receive any updates, we'll keep you posted.Best regards,Carlos A.

[idata · Accepted solution]

Well, looks like the problem was with a change WCU makes to the "Receive Segment Coalescing State" value.

Prior to updating to WCU "Receive Segment Coalescing State" is set to "disabled"

After updating to WCU "Receive Segment Coalescing State" is set to "enabled"

I ran "netsh int tcp set global rsc=disabled", verified it took with "netsh int tcp show global" and now I get full 150/150 on Miracast when running WCU.

Not sure exactly what this does (or doesn't do when disabled) but I was starting to worry as from what I've been reading, this laptop is actually geared toward taking advantages of the features of WCU.

[idata]

Hello mb2k,

Thank you for sharing your solution with us, I'm sure many other users will find this helpful.From what I understand, Receive Segment Coalescing joins the information from multiple data packets into one, decreasing CPU saturation (or that's what it's supposed to do, at least). Why this was enabled all of the sudden with this new update, who knows. But we're glad you were able to figure it out and resolve your issue.Best regards,Carlos A.

[bvk]

Just noticed the same issue, during a local network transfer of a file while using miracast. I was getting about 3-7 Mbps transfer speed which was unacceptable. Checked the solution and after changing the value of "Receive Segment Coalescing State", i went back to full Wifi speed.

Thanks

Ps: I also have a Spectre Laptop with the same Network card.