I have had a 10Gbe network at my home for sometime now, I am using the NETGEAR 8-Port 10G, Cat7 cables all the way. I have 4 devices hooked up to the network:

  • Router (Running PFSense) - Dell Dual 10Gbe NIC
  • R710 Server - Dell - Dual 10Gbe NIC
  • Synology Diskstation DS1817 - Built in Dual 10Gbe Nic
  • Desktop PC - Single Asus 10GBE Nic

When I do an iPerf3 test between any two of the devices (with the exception of the NAS as I can't), I get somewhere between 2Gbits/sec to 2.9Gbits/sec.

I have seen videos where people get faster speeds, in fact, near 10gbe.

Why can't I? What is my bottle neck? Is it my switch, and if so how can I tell?

Here are some screen shots of my Dell Server:

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And a screen shot of my PC enter image description here

What can I do next to determine why my speed is slow?

  • 2
    Have you tested between any device and the router? Or is this only always via the router? try using the iperf3 --parallel switch with a higher number than the default 2, as the default number of threads may not be enough to max the bandwidth. – harrymc Sep 2 '19 at 19:10
  • It is from and to any device. – Bill Daugherty Sep 3 '19 at 0:15
  • Have you tried hooking up your two fastest machines back-to-back without the switch, to eliminate the switch? Also, what TCP receive window is being used? If you force it to 1MiB, do you get better performance? – Spiff Sep 3 '19 at 2:46
  • 2
    Have you tried a higher --parallel number? – harrymc Sep 3 '19 at 6:28

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