Hi, i just installed a new 10gb network card in my unraid server and have a matching card in my pc but for some reason my actual network speed is bouncing around a lot. i'm using iperf3 to test and it will start of at about 4gb, then over the course of the test it will slow down to under 1gb. Previously i was using a 2.5gb nic in my server and i was able to get a stable 2.5gb using that, so i'm unsure what's gone wrong here

tower-diagnostics-20220609-1121.zip

Jun  9 11:21:41 Tower kernel: ixgbe 0000:01:00.0 eth1: NIC Link is Down

Jun  9 11:21:44 Tower kernel: ixgbe 0000:01:00.0 eth1: NIC Link is Down

Jun  9 11:21:45 Tower kernel: ixgbe 0000:01:00.0 eth1: NIC Link is Down

Link is constantly going up and down.

is there any reason the link would keep going down like that? did i configure something wrong?

That doesn't look like a configuration issue, most likely cable, NIC, transceiver, switch, etc

 

 

well i guess i new get to find out what doesn't work. would you say that as i have a second of the same card running to the same switch that i can probably say the switch isn't the issue?

i think i fixed my issue. I switched the two cables plugged into the switch end and now it works. maybe it just wasn't quite in properly or something. but it now seems to work

Cables are the major point of failure when it is about 10Gbe and UTP.

Note that you can buy quite a lot of "Cat.7 raw cables", but still only a handful of plugs that are capable of doing stable 10G.

Sadly, they are optically almost identical, but you can tell a difference, if you put them in. The bad cables dont lock in properly, you can move them a bit forward and backwards. The real ones snap in and are totally fixed in place.

I spend a lot of try&error buys before I gave up and switched over to fiber (which is rock solid!). Funnily the best working utp cables I found came from Amazon, search for "CSL - 0,5m Cat 7 Netzwerkkabel Gigabit Ethernet LAN Kabel - Baumwollmantel - 10000 Mbit S - Patchkabel - Cat.7 Rohkabel S FTP Pimf Schirmung mit RJ 45 Stecker - Switch Router Modem Access Point".

But be aware, that if you go over 30m in length, its more or less a coin toss. Stay below 10m if possible.

 

for anyone that finds this post in the future. this issue was my transceivers. i was using direct attach 10m copper cables and my switch didn't like them. Swapping to optical transceivers fixed the problem