Slow ethernet on 2020 iMac

[jiminoz]

I have an i7 2020 iMac and have gigabit internet. My download speeds on other computers in the house are about 930 Mbps. If I connect my 2020 iMac with a USB C to Gigabit ethernet adapter that is the speed I get. If I go through the gigabit ethernet port I get about 630 Mbps. My 2012 iMac gets full speed through the ethernet port. I have done enough troubleshooting to say, it is not the cable or the router. I have the network settings exactly the same on the 2012 iMac and my MacBook Pro. How do I troubleshoot this and what might be the cause of the slow speeds?

 

[chris_nlp]

Hi! same problem here. New imac 27 (i5) that replaced my late 2012 imac. network ethernet performance is much slower. transferring data to/from nas 500-750mbit/sec on big file transfer over afp protocol. old mac and macbook pro (with wired usbc nic) get 1000mbps flat. Switch is HPE 1820-8G-J9979A, no errors on port statistics an port is on 1000.

i will try windows vm in parallels bridged mode, see what that does.

Btw, there are no errors on my mac. Think it's a software or firmware thing that will be fixed in an update.