Ethernet bandwidth issue between RBSXTG-5HPacD and RB750GL

Hi,

I’m facing a big bandwidth problem while interconnecting a RBSXTG-5HPacD (RouterOS 6.20) to a RB750GL (RouterOS 5.25).
The 2 devices are connected with a Ethernet CAT-5E cable, auto-negociation, 1 Gbps (both have gigabit ethernet ports).
I checked with an other cable and 2 others devices, unfortunately with the same results.
The systems are clean : there is no queue rule, no firewall rule and the MTU is the default one.

I’ve done some bandwith tests (Mikrotik tool) and I get the following results :

  • Direction : from RB750GL to RBSXTG-5HPacD / Protocol : UDP / Max bandwidth : 480 Mbps
  • Direction : from RB750GL to RBSXTG-5HPacD / Protocol : TCP / Max bandwidth : 150 Mbps
  • Direction : from RBSXTG-5HPacD to RB750GL / Protocol : UDP / Max bandwidth : 480 Mbps
  • Direction : from RBSXTG-5HPacD to RB750GL / Protocol : TCP / Max bandwidth : 52 Mbps

Of course, the last result is the problem, and I can’t figure out why the TCP bandwidth, in this scenario, is limited to 52 Mbps…

PS : For those who are going to say that it’s not a good idea to do bandwith test directly from RouterOS because of the CPU usage, I’ve done the same with 2 Linux with iperf, and I get pretty much the same result.

Any idea ?

Thank you.