CRS326--CRS326, SFP+ only ~700mbit via 10gbit link. Slow performance or bottleneck?

Hardware MikroTik hardware general
1

Hi,

I have a setup:
2x MikroTik CRS326-24G-2S+RM (800MHz CPU, 512MB, 24xGLAN, 2xSFP+cage)
interconnected with 60m long single-mode fiber and SFP+ single-mode modules (Ubiquiti UF-SM-10G).

Connection was plug-and-play, 10Gbit link speed is up, however winbox bandwidth test shows speeds lower than gigabit (500-750mbps).

Where is the issue with my setup? I have tried to use secondary SFP+ ports on mikrotiks, I have tried to change the fiber cable.

a) is the Mikrotik CRS326 too slow to actually deliver >1Gbit speeds?
b) is the bottleneck somewhere else?
c) am I missing something?

Thank you
bandwidthtest.png
sfpstatus.png

2

Your device is a switch. It can work as a router, but that router is pretty weak. Basically, while switch hardware is powerful enough to forward L2 traffic between all the ports at wirespeed, the CPU of the device is not powerful enough to route the same amount of traffic. Btest is also CPU bound.

3

I use it as a switch.
SFP+ ports are part of the bridge1 LAN, there is no WAN, no NAT and no firewall.

4

You are testing on the device itself ?

You need to test from devices connected beyond the switches, eg iperf between PCs, the CRS does not have enough CPU to run btest.

regards
Nick

5

Thats easy. The switch has not the CPU resources to generate or receive 10Gbps.

You have to test with two beefy servers with 10GbE-NICs and iperf.

6

Thank you all.

Mikrotik should improve a GUI a bit.
Either show “CPU load” info box directly in the “Bandwidth test” dialog. It could turn red when load hitting 100%.
Or there could be a more explicit message in the status bar, like “running… CPU hitting 100%, btest may not generate enough traffic.”

So the user immediately knows when the measured data are useless.

7

Or you can read the test results on the MikroTik Website and see that the switch is benched for ~1Gbit/s of L3 traffic.

8

Alternativly, you can add a CPU-display on the topbar of Winbox? (Right click the bar below the window-line and select “Add CPU”)