Windows 11 Max network copy throughput of under 250mbps on a 1gbps network - why so slow?

Hello x10bulls,
Your situation with the NAS transfer speed is indeed puzzling, especially when you're connected to a gigabit network. Let's break down a few potential culprits for your throughput issues.

Potential Factors Influencing Network Performance​

1. Network Configuration:
   • Ensure that the Ethernet connections are properly configured. For a 1Gbps connection, both your NAS and router must support gigabit speeds, which seems to be the case for your Synology DS216SE and TPLink AX1500.
   • Check the network settings on your PC. Navigate to the Network and Sharing Center and ensure the connection is set to "Gigabit" mode, not a lower speed configuration.
2. Cable Quality:
   • Double-check the Ethernet cables being used. For gigabit speeds, you should ideally use CAT5e or CAT6 cables. Older cables like CAT5 might limit throughput.
3. NAS Settings:
   • Look into the NAS settings and confirm that it’s set to use the maximum available connection speed. Some older devices may have limitations based on their firmware or configuration settings.
4. Network Traffic:
   • During your transfer, monitor for other network activities. If other devices are heavily using the network, this could impact your speed.
5. Software Configuration:
   • Antivirus or firewall software might also throttle network performance. Temporarily disabling these (with caution) during your transfer may help illuminate the issue.
6. Windows 11 Specific Issues:
   • Windows 11 may have certain networking issues or settings that could be affecting throughput. Ensure your system is up to date with the latest patches and updates.
7. Performance Graph Misinterpretation:
   • The performance graph showing 250 Mbps may relate to network protocol behavior (TCP overhead, for example), not the effective data transfer rate. Throughput is often affected by multiple factors including signal interference and bottlenecks in the network path.

Image Analysis​

From the attached image, it seems to reflect the network performance metrics on your system, showing varying throughput. Unfortunately, it highlights the limitations of monitoring tools that sometimes combine bits of different metrics that could create misleading impressions about actual speeds.

Next Steps​

I recommend performing a few tests:

• Run a speed test on your network using tools like iPerf between your NAS and PC to measure raw throughput.
• Check NAS firmware updates; keeping the device updated can often resolve unexpected performance issues.

By systematically checking these factors, you should hopefully identify the bottleneck causing the reduced transfer speeds. If you have any more details or updates, feel free to share!