[SOLVED] Download speed throttled on just 1 device, latency & upload uneffected

[rpj]

Hi and thanks in advance,

We have a Lenovo ideapad 320 on our network which is unable to download more than 1-2 Mbps via wifi. Brief overview:

• connection is fine when on ethernet
• changing networks or wireless receivers has made no difference
• problem arose sometime in the last few months, but I don't know exactly when
• no other device on tested networks is getting slow download speeds
• latency & upload speeds are unaffected

Computer Specs:

• Windows 10 Home 64-bit 10.0, Build 19042
• Lenovo model 80XL
• Intel(R) Core i7-7500U CPU @2.7Ghz (4 CPUs), ~2.9Ghz
• 8192MB RAM
• Wireless adapter: Inter(R) Dual Band Wireless-AC 3165 (driver 19.51.31.1)
• I was unable to determine make/model of power supply and motherboard

The wireless network is:

• Netgear R6250
• Firmware version V1.0.4.38_10.1.30
• 9 devices on network, this is the only one with any connectivity issues
• Comcast is the ISP

The wireless for other devices comes back around

• 10 ping
• 27-30 Mbps down
• 1-2 Mbps up

For this device, the only difference is that the download speed is consistently under 2 Mpbs

Troubleshooting so far:

• Ran Windows networking troubleshooter, which came back with no flagged issues
• Shut down as many background processes as I could find, testing the connection after shutting each down
• Plugged in and updated drivers for 2 external wireless receivers via USB -- these receivers both work on other computers in the house but made no difference on this laptop
  • During this process, I also tried shutting down all network devices other than the one being actively used for the built-in wifi receiver as well as the two external receivers
• Tried multiple speedtests in multiple browsers, each with other browsers shut down, and saw no significant variations
• Moved to multiple rooms to test signal strength and saw no significant difference, even when right next to the wireless router
• Reset both router and modem, then repeated occasionally during troubleshooting
• Did a full system scan with Malwarebytes and found 0 results for possible malware
• Unchecked "Allow the computer to turn off this device to save power" under the wireless adapter's power management settings
• Tried multiple networks (two via this router, one via phone hotspot).
  • One wifi channel is 2.4 Ghz with WPA2-personal security type
  • One wifi channel is 5 Ghz with WA2-personal security type
  • A separate wifi network was via cell phone hot spot
• Tried turning off windows firewall (turned it back on when it had no impact)
• Reset the computer at various points throughout this troubleshooting process, which has taken place over several days

The download throttling does not appear to have a relationship with RAM or CPU usage, no have I been able to find a meaningful relationship with any specific program or process.

Strangely enough, Zoom also seems able to connect to calls without an issue, even while speed checks are reporting download speeds at under 1Mbps.

While network download speed appears throttled, resource manager says the computer is only using 1-5% of networking resources even though the PC is acting as though there is no network resources left. I also verified that metered connection is off, and for good measure I tried toggling airplane mode.

I also checked to see if my network has a QoS priority rule that would be giving Zoom more access than other applications, but it does not.

I'm out of ideas. If you got this far, thanks for your help.

 

[T_T]

Since you didn't specifically mention as to whether or not you changed USB ports on the laptop, I suggest you try moving the adapter(s) to a different USB port, preferably a 3.0 or higher port.

Also worth considering are the network settings for the laptop. While unlikely to be the cause, you didn't mention if you had checked or reset the laptop's network settings. Do this:
Windows+I>Network & Internet > Status > Network reset then allow the computer to restart.

 

[rpj]

Since you didn't specifically mention as to whether or not you changed USB ports on the laptop, I suggest you try moving the adapter(s) to a different USB port, preferably a 3.0 or higher port.

Also worth considering are the network settings for the laptop. While unlikely to be the cause, you didn't mention if you had checked or reset the laptop's network settings. Do this:
Windows+I>Network & Internet > Status > Network reset then allow the computer to restart.

Absolutely good advice. I have tried the wifi receptors on multiple USB ports and the primary receptor is built-in to the laptop.

Per your advice, I have done a network reset. There was an initial improvement but it degraded within 4-5 minutes -- I suspect the short-lived improvement is due to restarting the computer, which sometimes has a brief positive effect.

 

[T_T]

Interesting. Perhaps you could make some use of Wireshark to analyze your traffic, specifically, at the moment the performance degrades. This should give you an idea of what to do:
How to Use Wireshark to Analyze Network Performance (perforce.com)

 

[bill001g]

Using a different wifi adapter should have solved most problems. It should be different hardware and likely different drivers. I guess you could try drivers directly from the chipset manufacture or maybe lenovo. You want to avoid the generic ones microsoft loads....and sometimes even loads over the top of one you had when you let it update windows.

These laptops sure went to crap after IBM sold out to lenovo. They do stupid stuff, I have seen more than once people posting here and their fairly modern laptop only have a 10/100 ethernet even tough the chipset supports gigabit. Never figured out why they did that.

What you might be able to do but it hard to say on lenovo is boot a USB linux image. This will quickly show if there is some hardware issue or if it something hiding in the window OS. If it work on linux normally the next step is a clear windows 10 install but with lenovo I would be very careful to see if they have any instructions on their site. You would need at least the drivers for the motherboard which likely also comes bundled with the wifi drivers.