[SOLVED] 2.5BASE-T NAS Downloads Slower than Gigabit

therrake

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Jan 25, 2011
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I recently installed TRENDnet 2.5BASE-T PCIe network adapters (TEG-25GECTX) in my home server (setup as a NAS) and main rig. Systems are setup to access the internet using their built-in Gigabit ports. The 2.5BASE-T cards are directly connected to each other with a Cat6A cable. They live on their own subnet to (theoretically) enable faster file transfer speeds. The server is running a Samba share linked to a RAID 1 array. (system specs below)

Iperf and NAS Performance Tester benchmarks confirm that the 2.5BASE-T card should be faster than the gigabit connection (not a surprise). (screen caps below)

When I upload files to the server from my PC, actual 2.5BASE-T speeds exceed those of the Gigabit link. (screen caps below)

However, when I download files from the server to my PC, actual Gigabit link speeds exceed those of the 2.5BASE-T card--by nearly twofold. This has proven consistent across various tests. (screen caps below)

Why is gigabit outperforming 2.5BASE-T in download speed? How can this be fixed?

Server:
Dell T110 II running Ubuntu 20.04
Samba install sharing a RAID 1 array
TRENDnet 2.5BASE-T PCIe network adapter
2x 4TB SAS 6.0GBPS 7200 RPM

Main rig:
Ryzen 5 1600AF on Windows 10
TRENDnet 2.5BASE-T PCIe network adapter
WD Blue NVMe M.2 2280 500GB

Upload 2.5Base-T Link:
25-upload.jpg


Upload Gigabit link:
1-upload.jpg



Download 2.5BASE-T Link:
25-download.jpg


Download Gigabit Link:
10g-download.jpg




Iperf 2.5BASE-T Link Test:
25-iperf.jpg


Iperf Gigabit Link Test:
1g-iperf.jpg


NAS Performance Tester 2.5BASE-T Link Test:
test25.jpg


NAS Performance Tester Gigabit Link Test:
1-test.jpg
 
Solution
Confirmed there are no default gateways set. Unfortunately, the 10.x.y.x solution did not address the download speed issue.
Linux requires tuning for high speed networks. Assuming your NAS is running a Linux OS, you should research network tuning for 10GE on Linux. That may help.
Even Windows may require tuning.
Very strange indeed. You've done everything I would have and have gotten puzzling results. I would guess this is somewhere in the driver for the 2.5g nic, but it's odd that it only affects the file transfer test and not other tests. What version of smb are you running on each link and each end (client and server)?
 

therrake

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Very strange indeed. You've done everything I would have and have gotten puzzling results. I would guess this is somewhere in the driver for the 2.5g nic, but it's odd that it only affects the file transfer test and not other tests. What version of smb are you running on each link and each end (client and server)?
I greatly appreciate the reply and sanity check! Ubuntu is running Samba 4.11.6 (from Samba Status). The Windows box is running Samba 1.0 (from Windows control panel). I plan to investigate possible driver solves tonight. Will update the thread if that fixes the issue.

Thank you.
 
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therrake

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The 2.5 Gb network with a 2.x.y.z subnet could be a problem. That is a routable IP address. I would use a 10.x.y.z if your internet is on 192.168.x.y also ensure you don't have a default gateway on the 2.5Gb ports.
Confirmed there are no default gateways set. Unfortunately, the 10.x.y.x solution did not address the download speed issue.
 
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Reactions: SamirD