My understanding from the wikipedia web page for Duplex and from StackExchange solutions like this is that on a contemporary ethernet connection the transmit site visitors is meant to be unaffected by the obtain site visitors. However I am operating some exams between two trendy Mac computer systems and I am seeing outcomes that make me suppose there’s one thing essential I am lacking in my understanding.
The check rig is 2 Mac Studio M2 Extremely containers, one with Ventura v13.7.4 and one with Sonoma 14.7.4
So as to scale back complexity, I’ve related them straight to one another with a brief CAT6 copper ethernet cable between their built-in NICs. Once I let it auto-negotiate the pace it says 10GbaseT as anticipated, and for a part of the check I set it to handbook and 1000baseT
System Preferences > Community > Ethernet > {Hardware} (and ifconfig) say Full Duplex in each modes
At 10GbaseT, utilizing a finder copy on Mac A, copying from the native drive on mac A to the native drive on mac B, I get ~1200 MegaBytes/sec as anticipated (transmit-only)
At 10GbaseT, utilizing a finder copy on Mac A, copying from the native drive on mac B to the native drive on mac A, I get ~1200 MegaBytes/sec as anticipated (receive-only)
At 10GbaseT, utilizing a finder copy on Mac A, copying from the native drive on mac B to a different share of the native drive on mac B, I get ~650 MegaBytes/sec (simultaneous transmit/obtain, just a little over half pace)
[I get similar results running two copies at once, one transmitting and one receiving]At 1000baseT, utilizing a finder copy on Mac A, copying from the native drive on mac A to the native drive on mac B, I get ~120 MegaBytes/sec as anticipated (transmit-only)
At 1000baseT, utilizing a finder copy on Mac A, copying from the native drive on mac B to the native drive on mac A, I get ~120 MegaBytes/sec as anticipated (receive-only)
At 1000baseT, utilizing a finder copy on Mac A, copying from the native drive on mac B to a different share of the native drive on mac B, I get ~65 MegaBytes/sec (simultaneous transmit/obtain, once more just a little over half pace)
[Again, similar results running two copies at once, one transmitting and one receiving]
What offers? It isn’t simply Finder, as a result of terminal instructions to repeat do the identical factor. It isn’t crappy third celebration {hardware}, I am utilizing the built-in ethernet. Even when there was some {hardware} limitation within the NIC, or an issue with storage pace, would not it at the very least be capable of get full 1GbE pace concurrently sending/receiving in 1GbE mode?
The explanation we went testing is as a result of we’re seeing related efficiency utilizing switches and connecting to an precise fileserver, the check rig was simply to remove variables. Auto-negotiating to a single 1GbE change in between the 2 check containers did not repair it, and I attempted NFS which did not appear to make a lot distinction. Jumbo Frames (MTU 9000) helped considerably, it acquired as much as about 85 MB/sec, but it surely did not go all the best way to the identical pace as one-way copies, and we will not use Jumbo Frames in manufacturing sadly anyhow.