Slow transfer speed to local NAS on PC1 and normal transfer speeds on PC2

Question

Hello everyone, I am desperate at this point to try and find out what is happening! Basically I have a WD NAS (EX4100) where the normal local transfer speeds over the network are arround 100Mb/s, wich all my pcs archived up to this point. After changing my motherboard a couple of days ago the speeds on my main PC, the one with the MOBO swap droped to 30Mb/s, like they are capped. This happened straight after installing windows without me even instaling anything on the PC! The other one still transfers at normals speeds but this one acts like its limited! It's worth mentioning that downloads from the web are normal go up to the 100Mb/s wich are ok acording to my ISP and the nVMe is in perfect working conditions. I have tried everyhting at this point, different drivers, switching over to wifi... if you think it, I have tried it!

My question is, what could possibly be causing this? Hardware, in this case the MOBO swap? or Software, windows or the NAS?

Thank you!

***moved from Windows / Windows 11 / Internet and connectivity ***

Answer 1

Hello ,

Thank you for posting in Microsoft Community forum.
Based on your description, here are some of the hardware and software factors that can cause this issue, as well as the solutions you can try.

1. The network adapter on the new motherboard may not be configured correctly. Check your network adapter's settings to make sure its speed and duplex mode are set to Auto-Negotiate.
2. Even though you mentioned that you've tried different drivers, it's important to make sure you have the latest network adapter drivers installed. Visit the motherboard manufacturer's official website to download and install the latest drivers.
3. Check the network cables connected to the NAS and PC1 to make sure they are not damaged and support the required speed, at least Gigabit Ethernet. Try plugging the cable into a different port and see if that improves.
4. Check the settings of your NAS and make sure that there are no bandwidth throttling options enabled. Some NAS devices may have QoS (Quality of Service) settings that may affect the transfer speed.
5. Make sure that there is no bandwidth limit in the network settings of Windows. You can try disabling Network Traffic Monitoring or QoS Packet Scheduler for Windows.
6. Check the settings of your firewall or any security software to make sure they are not restricting network traffic.
7. Make sure PC1 and NAS are on the same network segment and there are no IP address conflicts. You can try setting the IP addresses manually to make sure they are within the same subnet.
8. Although less common, a new motherboard may have a hardware failure that is causing the network adapter to perform poorly. You can try using a USB network adapter to test if it's a network interface issue with your motherboard.

I hope the information above is helpful.

If you have any questions or concerns, please feel free to let us know.

Regards,
Jill Zhou

Answer 2

Hello, thank you for the tips.

1. This has been done, auto negotiate was confirmed.
2. The latest drivers have been installed, although I tried diferent ones the latest one is the one I most tried to make it work with.
3. Checked and rechecked the cables, replaced them a couple of times and the same result was archived. (all cables gigabit capable)
4. I have double checked my NAS admin panel and it's a very simple NAS, doesn't have any QOS features, it's a WD Ex4100. Nothing seems to be enabled that would affect it, and since my PC2 receives and uploads at full speed I discarded the possibility of being the NAS.
5. This point seems like the most probable cause, some quind of throttling happening on windows, I ahev tried to search for it and so far haven't found anything, I did try to disable the qos on the network card but didn't help. So I am a but lost when It comes to any qos windows might be applying.
6. I don't have any security software but I also haven't gone to deep into the firewall, since it was defaulted straight after inta long windows, I will double check this.
7. All IP addresses on the network are manually assigned, so I wouldn't have any conflicts in this section.
8. This was the last thing I tried, yesterday, with an external USB Ethernet stick, and the same thing happened, so I would say it's not the motherboard, altho I did ask for help to the mobo manufacturer.

All has been tried and I still have no idea what is happening and why would this be happening.

Answer 3

First of all, I'm very sorry that I missed your reply.

Thank you for your feedback.

From your description, you have ruled out most common reasons, but there is still a speed limit problem. Here are some further suggestions:

1. Check the Windows transfer protocol settings to confirm that your Windows does not enable settings that limit transfer speeds, for example: open "Control Panel" -> "Network and Sharing Center" -> Current Network Connection -> "Properties" and disable the "Large Send Offload (LSO)" option. In the registry, check HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters and make sure the DisableBandwidthThrottling key value does not exist or is set to 1.
2. Some network problems may be caused by uninstalled updates. Please make sure that Windows is updated to the latest version.
3. Your NAS may be using the SMB protocol. Try to enable or disable different versions of SMB (SMB 1.0 or SMB 3.0) in "Windows Features".
4. Even if you use the same switch, some of its ports may have performance issues. Try changing the network switch or connecting the NAS to another device to test directly.

If the above operations still do not solve the problem, consider reinstalling Windows to rule out the possibility of abnormal system configuration, or use performance monitoring tools (such as Wireshark) to capture network traffic and analyze whether there are abnormal patterns.

Looking forward to your further feedback, we will do our best to help you solve the problem!

Answer 4

It seems, OP is no longer responding, but since I have the exact same Issue, I'll continue this.

1.)

As Pedro said, he is on a completely fresh installation of Windows, so I doubt any Windows Network Settings are set wrong. As for Bandwidth throttling, that Setting is for throttling Internet Traffic, but he already said, that is fine, downloads work with full speed, way past the 30MB/s Limit we see here. The Issue is only in the local network

2.)

Windows is freshly installed and Up-to-Date

3.)

NAS can't be the issue, as Pedro said, it works with full speed from other computers in the network.

4.)

Can't speak for Pedro, but only the computer was switched, the cable to the router hasn't changed, and the port on my Switch/Router is set to full 1G Speed, I checked.

I don't think re-installing windows is the answer her, as stated, this is already a freshly installed Windows.

I just re-installed the network driver from the Mainboard manufacturer, but it didn't change anything. What I assume where the problem (for me) is coming from, for the first time on this Motherboard, the LAN port is capable of 2.5G LAN Speeds, but my Router and NAS is only 1G and that this might cause an issue.