Odd slowing of internet speed on one PC

[#1]

Hi

Can anyone shed any light on this please?

I'm on 500 FTTP and it's stable and rock solid at 512Mbs/71Mbs (shown on SamKnows). 

However, our main Win 11 PC which is connected via Ethernet, seems to suffer a lowering of internet speed throughout the day. If I reboot the computer, then doing a speed test it instantly goes back to 500ish, but redoing the test a few hours later the speed can be as low as 4Mbs (maybe lower). Again, a reboot temporarily solves the issue. 

In Task manager, the network tab, show little internet activity and the processes also show little network at 0%

Other devices on the same network are showing a normal speed.

The computer is a few months old, with I712700F processor and 3060Ti GPU.

Thanks

[#2]

@minkey  I had seen a similar problem earlier this year but it was concerning upload speed, but it might be worth checking the type of ethernet hardware on the PC, try the tests in message #29 in this thread.....

https://community.plus.net/t5/Full-Fibre/New-Full-Fiber-customer-miserably-slow-upload-speed-0-26Mb/... 

Is the PC connected directly by ethernet cable to the ONT? If not that would be worth trying. It's difficult to figure out why the speed is OK after reboot but falls away.🤔

[#3]

Thanks @RealAleMadrid 

I updated the drivers for the Ethernet to see if that improved things. It didn't ☹️

IPCONFIG shows this and I can't see anything amiss in the ROUTE PRINT...

Windows IP Configuration

Host Name . . . . . . . . . . . . : WINDOWS-xxxxx
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : home

Ethernet adapter Ethernet:

Connection-specific DNS Suffix . : home
Description . . . . . . . . . . . : Intel(R) Ethernet Connection (17) I219-V
Physical Address. . . . . . . . . : A0-36-BC-36-26-F6
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::e161:3732:4708:171c%13(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.248(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 20 October 2023 13:05:44
Lease Expires . . . . . . . . . . : 21 October 2023 13:05:43
Default Gateway . . . . . . . . . : 192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DHCPv6 IAID . . . . . . . . . . . : 111163068
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2B-AA-24-07-A0-36-BC-36-26-F6
DNS Servers . . . . . . . . . . . : 192.168.1.254
NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter Ethernet 2:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : TAP-Windows Adapter V9
Physical Address. . . . . . . . . : 00-FF-E1-0F-25-20
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Bluetooth Network Connection:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Bluetooth Device (Personal Area Network)
Physical Address. . . . . . . . . : 00-1A-7D-DA-71-15
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Teredo Tunneling Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv6 Address. . . . . . . . . . . : 2001:0:14be:4c8:1cb0:1042:2bc7:99c2(Preferred)
Link-local IPv6 Address . . . . . : fe80::1cb0:1042:2bc7:99c2%14(Preferred)
Default Gateway . . . . . . . . . : ::
DHCPv6 IAID . . . . . . . . . . . : 218103808
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2B-AA-24-07-A0-36-BC-36-26-F6
NetBIOS over Tcpip. . . . . . . . : Disabled

Before and after a reboot speed test...

[#4]

@minkey there are a few posts out there regarding slow performance with the i219-v

see https://www.intel.com/content/www/us/en/support/articles/000058667/ethernet-products/gigabit-etherne...

This

If the system comes with TurboLAN Cfos, disable the service called cFosSpeed System Service. 

seems significant

https://www.reddit.com/r/HomeNetworking/comments/mfc234/slow_wired_speeds_on_pc_intel_i219v/

[#5 · Accepted solution]

@MisterW  That's interesting, it's always worth checking the ethernet hardware type for any weirdness and  gives @minkey something to investigate.

A quick test is starting the PC in safe mode which should run at full ethernet speed according to the Intel link.

[#6]

Thanks @MisterW 

Ok, so I had a spare wireless dongle and connected via that and the speed was still low, so that eliminated the Ethernet card. I didn't have TurboLan or CfosSpeed installed either.

Also thanks @RealAleMadrid  - Running it in Safe Mode, it remained stable at 500/70 for prolonged time, so at that point it had to be software related.

My first (and final) thought was the firewall software, I have Zone Alarm Extreme Next Gen installed. Uninstalled that and et voila no speed loss! Been logged on for a couple of hours now and still at over 500Mbs 😀

Now need to work out what I do about my firewall/virus and whether to dump Zone Alarm 🤔

Thanks again

[#7]

@minkey  If you are running on WIndows 10 or 11.. you should not need any addtional firewall software running...

Probably caused your speed loss due to double working of WIndows and Zone Alarm conflicting at times.

[#8]

@shutter I'm going to see how Windows Defender performs and not use ZA. When ZA was installed though, Defender was disabled so unlikely to be double working, but the speed loss was definitely a pain...

[#9]

Just a quick note.. sometimes you make a change and it seems to solve it - only for it to come back a few weeks later.

I have a large pc with 8 cores and 16Gb of ram. It always used to keep me waiting 5 minutes before letting me in via remote desktop while the hard drive light was constantly on. Eventually tracked it down to one bit of software.. a few weeks later the problem returned, solved, returned, solved etc..

If this happens to you I'd swap out the Ethernet card. I have a WiFi adapter that seems to be dying. It will be fine for a few hours and then randomly despite a good signal the internet drops dead and won't work unless I disable it and then enable it again. Electronics can and do fail and can also become intermittent. It's rarer these days but does still happen.