one of 4 machines gets lower bandwidth

I have several machines in my office, all wired. My main system gets around 20% less internet speed than my other systems (70 odd mbps compared to 104<> on the other machines). I've tried connecting the main system to another router. Still slow, and I've connected other machines to the router of the main system and it provides over 100 MBPS.

I also tried installing another NIC. Performance is the same...70+ MBPS.

This tells me my issue is in machine itself, likely configuration.

Any ideas on what I can try to get the bandwidth on this machine up to speed?

Pertinent Specs:

Asus TUF Z370 Plus Gaming
i5 8600K
32GB DDR4 RAM

I'm Using theonboard intel NW with latest driver for my setup (12.15.25.6, circa 2017)
Device Manager shows card as Intel Ethernet Connection (2) I219-V
The Diagnostics button runs and shows no issues.
Link status shows 1 Gbps (EEE: Not negotiated).

Any help appreciated.

Thanks.

Couple things Four points:

A) If the Intel NIC (Network Interface Controller) had its properties changed, that could do it. Like jumbo frames and whatnot. Those settings are found by right clicking the NIC in Network Adapters and under configuration. You probably have not one iota what all that stuff means, so to default it all back I'd just uninstall the NIC's driver and software (preferably with Revo Uninstaller) and reinstall the driver/software again AFTER a system reboot.

B) Software like a firewall or anti-virus could do it. Even a driver. Something software wise could be choking off the Internet connection bandwidth. To help rule this out try safe mode with networking. To get into safe mode reboot the PC and keep tapping the F8 key. Now chose safe mode WITH networking. See if you have your full Internet speed. If so, then it's most likely a software or driver issue which I can try to help with.

C) Sometimes it's very, very simple. Did you try a new Ethernet cable? A lot of Ethernet cables and the plating on the pins are not well manufactured and tarnish/erode/ Looking at the pins with a microscope will tell.

D) Check the ACPI settings (power settings). Control Panel | Power Options. Or type power options in Windows search. There are low power modes for the NIC, USB devices and even PCI-e devices. This can cause issues.

Hi Simpilot. Thanks for your response.

I only recently compared the speed on different machines and discovered the difference. The problem machine has always tapped out at 70 mbps <>, so it seems to have been an issue for at least quite sometime. I had chalked it up to my NW setup (several subnets on my NW), but that turns out not to be the case.

A. I didn't uninstall the NIC yet (i'ts been a busy week), but, as mentioned in the OP, I did install a different NIC. Speed remained the same. 70<>.

B. I tried turning off my firewalls previously. No change.

What's interesting is that when I started in Safe Mode, no change. Still 70 mbps <>. After this, I immediately plugged the cable into one of my other machines and achieved 104 mbps multiple times. Plugged back into problem machine...70 mbps again.

C. As mentioned in B, I used the same cable on another machine and got 104 MBPS.

D. I did try this, but no change. I also assume that these PM settings aren't 'loaded' in Safe Mode.

I'm more baffled now. It must be some sort of HW limitation, but two different NICs with no change.

I apprecaite any help.

Anti-virus software can slow things down. So check that.

The nuclear option. tcp-ip-reset/source at main . 737simpilot/tcp-ip-reset . GitHub Enter those commands in an elevated CMD prompt.

I'm having doubts it'll fix it.

Have you rebooted the router? There could be an old stale router table that's doing it. Like a QoS setting or something tied to that machine's MAC address for the NIC. You should be able to give your NIC a new MAC address as well in its properties. A reboot may be required. MACs look like this. They are hexadecimal (0-1, A-F) and are 6 bytes long. As an example: 08:00:20:45:C3:A4

First three bytes are the OUI (Organizational Unique Identifier). This means this part 08:00:20 belongs to Oracle. The last 3 bytes are unique to the client. Now-a-days cellphones randomize this. Once upon a time you could track someone all over the world due to unique MACs assigned to a cellphone. LOL

Hi Simpilot and Samuria. Apologies for the delayed response, my business keeps me running this time of year.
@Simpilot:

Router reboot: Yes. In fact, I recently replaced the router on that subnet with an RT-AX86XU, Flashed to the latest Merlin FW.

I've looked, but don't see where to change the MAC in the properties of the NIC. Would the new router address the issue you mention?

@ Samuria:

I had a few issues finding the property sheet for the 104mbps machine (it's win 10), but all the values are exactly the same.

That was a good suggestion, especially given that both machines have the same motherboard/built-in NIC.


I also have checked the bios to see if there were any settings there that might somehow limit bandwidth, but didn't notice anything amiss.
Below is a screenshot of the win7 property sheet with NIC model.




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So, what does the router firmware look like? Is QoS on?

Is there more than one router connected in this network? You made sure there are no double NATs? WHat's the router firmware settings look like in the other routers if they exist?

To check for a double NAT condition, go into command and enter tracert 1.1.1.1

If you see the first two hops in the same CIDR, you have a double NAT condition.

The MAC address is changed in the option called Locally Administered Address. Advanced Settings for Intel(R) Ethernet Adapters

- - - Updated - - -

msalton1 said:

I only recently compared the speed on different machines and discovered the difference. The problem machine has always tapped out at 70 mbps

What are you using to measure the speed?

- - - Updated - - -

Have you tried the computer ---> router ----> modem? No other routers and whatnot in between?

The fact safe mode still exhibits this issue tells me it's hardware related. Unless there's a network related driver that's problematic being loaded in Safe Mode with Networking. We can see if that's the case with a program called Process Hacker. (It will trip anti-virus software). Click the Network tab. See anything out of character? Better yet, under the Network tab go to the top left under "Hacker" and Save the text file. Zip and upload that.

Sorry to drag this on. Very busy this year.
@Simpilot:

So, what does the router firmware look like? Is QoS on?

FW: RT-AX86U_386.7_2_pureubi (merlin). QOS off. FW settings look fine, AFAICT. No different thatn any other router I've set up. My routers are 3 asus and 1 TP-Link,

Is there more than one router connected in this network? You made sure there are no double NATs? WHat's the router firmware settings look like in the other routers if they exist?
To check for a double NAT condition, go into command and enter tracert 1.1.1.1
If you see the first two hops in the same CIDR, you have a double NAT condition.

No double NAT.

Yes, more than one router. The system in question is on an AX86U, as is the 'shield' router. I have 3 machines in my office, all are on their own subnet with their own router, all behind the 'shield' router.

What are you using to measure the speed?

testmy.net

Have you tried the computer ---> router ----> modem? No other routers and whatnot in between?

Yes. I've tried directly from router and directly from shield router. Still stuck at between 70-80 mbps. When I take same NW cable from same router and plug it into one of the other machines, 100-104 mbps. It's got to be something with the machine.

The fact safe mode still exhibits this issue tells me it's hardware related. Unless there's a network related driver that's problematic being loaded in Safe Mode with Networking. We can see if that's the case with a program called Process Hacker. (It will trip anti-virus software). Click the Network tab. See anything out of character? Better yet, under the Network tab go to the top left under "Hacker" and Save the text file. Zip and upload that.

Oddly, the other machine I test (and is getting 104 mbps) is the exact same motherboard/NIC.

I'm not seeing anything unusual in process hacker. What would I be looking for?

Obviously, this isn't an urgent matter. More a matter of just thinking I should get the bandwidth I'm paying for.

This strikes me as a very odd problem.

Summary:

• Machine gets only 70-80 mbps
• connecting NW cable to other machines = other machines getting expected bandwidth
• connecting machine directly to shield router (bypassing subnet router) still only gets 70-80 mbps (connecting to other machines results in expected bandwidth - 104 mbps)
• restarting in safe mode doesn't solve problem.
• using different NW card doesn't solve problem.

Again, thanks for any help.

Try this program:

SpeedGuide.net :: TCP Optimizer / Downloads



Try Optimized and Windows defaults, move the slider to the farthest right and just play with the values. If doesn't work, try uninstalling all the adapters you have. I notice that your adapter is ethernet connection (2), meaning there is or was an adapter with the same name before. A clean reinstall of the driver deleting all previous adapters from the registry wouldn't hurt.

Hi Diz. The only other NIC I've ever had in this build is a pcie Intel NIC I installed when I realized I was having the issue (after several attempts to figure it out). I haven't taken it out of the machine yet.

I also have uninstalled and reinstalled the drivers for the onboard NW (screenshot above, which is an onboard NIC for the Asus Tuff board).

I'll download SpeedGuide utility you suggest tomorrow and post back. Thanks for the help.