Receiving only 2.5Gb in one direction with unusual issues
Receiving only 2.5Gb in one direction with unusual issues
Hello everyone, I've just configured a 2.5Gb connection between my NAS (operating TrueNAS) and my desktop. My desktop's motherboard originally supports 2.5Gb, but I added a NIC to the NAS and purchased a QNAP 2.5Gb/10Gb switch. I was experimenting with different setups using iperf3 and noticed that initially, speeds exceeded gigabit from NAS to desktop. I then tried using the onboard gigabit port both with the new switch and with everything connected through the router as before. Through the router, I received consistent gigabit speeds in both directions. When I added the new switch and connected it to the NAS's motherboard gigabit port, performance remained stable. However, when using the switch directly on the NAS side, speeds dropped significantly. Interestingly, connecting via the new NIC resolved the issue, except for the limitation of gigabit traffic going from desktop to NAS. I've attached screenshots of the iperf3 results below. Any insights into why these issues occur? Router Only – Spoiler: Desktop → NAS → Desktop with New Switch (Gigabit Motherboard) → +2.5Gb NIC Spoiler: Desktop → NAS → NAS → Desktop Spoiler: Overall performance is around 90MB/s, which seems low. I suspect my RAID setup might be incorrect, though this isn't a major concern since I'm planning a fresh array soon.
Consider linking the NAS and your PC directly via one cable and performing a test connection. This will help identify if the issue lies with the switch or one of the devices. You might also install a live OS from a USB on both the NAS and your PC (for example, Ubuntu 22.04 LTS) and execute an iperf test to check for driver or network card problems.
I tested the directly attaching concept and achieved the same 1.07Gb/s speed with Desktop to NAS. When trying the opposite direction, it froze and didn’t respond. This happened regardless of using the NIC or the onboard device. I reverted to Switch+NIC to confirm everything was intact and it functioned properly. The NAS to Desktop connection stabilized at a consistent 2.37Gb/s, unlike the previous instability. I plan to explore the USB boot method tomorrow to see if it helps.
I tried it recently and achieved about 2.35Gb/s in both directions, which suggests the hardware is functioning properly. I didn’t check the unusual behavior on the NAS motherboard’s Ethernet, though. Could this be a driver problem, then? It seems likely on one side, possibly Windows-related and potentially fixable.
My gaming laptop had serious issues, it seemed completely damaged with the included hardware. Even after a fresh Windows install, the problems persisted. It might have been resolved over time through a Windows Update, meaning some unique compatibility issues between the device and the operating system. On my current Win11 PC, speeds fluctuate—around 2.37Gbit download, 1.77Gbit upload—but on Linux systems I consistently experience smooth performance. I’ve also noticed that iperf3 can show slower transfer rates while actual file transfers remain fast.
Wow, that actually works! It looks like the Windows driver was outdated and wouldn't update. I removed it and used the utility from Realtek's site. I'm seeing about 2.35Gb in both directions, which is great. I can copy files to the NAS at full speed, but I haven't tested the reverse yet—maybe because of my hard drive limits. I'm looking forward to installing new drives in a few weeks and hearing good news!