After upgrade from 5.8 to 5.11 we haved troble with very big latency on the ethernet ports.
See the graph below there is very easy to recognize upgrade to 5.11 and downgrade back.

There is one 10 Ghz link with low latency , but after upgrade was the latency much bigger.
One side its RB1100 ETH12 and the second RB800 ETH 1

Please let me know if you will release some stable version, thank you.

We had the exact same problem on ether9 and 10 on a RB1200. Support said that it appears to be a side-effect of the fix to avoid board-locking due to traffic on those two ports.

Is your latency limited to specific ports?

edit: nevermind, you specified that in your note. Do you have free ports on ether1-ether8 on the RB1100 you could move to?

Thank you for the report. This problem will be fixed in RouterOS v5.12. Only RB1100 ether11-ether13 and RB800 ether3 ports are affected by this problem.

Thank you

The failure is not fixed in this version ?

What's new in 5.12 (2012-Jan-19 14:31):

*) console - allow to specify blank interval on x86 screens;
*) console - changed 'password' command, now can be used from scripts and api;
*) winbox - reorganized window layout to match console better;
*) ssh - fixed interoperability problem with psftp based clients;
*) implemented simple SMB (windows file sharing) server;
*) fixed ovpn-client - client stopped working if it was enabled/disabled at wrong time;
*) fixed ipv6 - ipv6 neighbor discovery stopped working when
interface arp setting wasn't set to enabled;
*) console - minor fixes and improvements;
*) console - added support for compact export;
*) hotspot - added login redirect through http status 302;
*) leds - added default configuration for R5SHPn wireless card;
*) ppp - fixed problem were remote-ipv6-prefix was not given to user if remote-ipv6-pool was
provided;
*) winbox, webfig - sort ethernet interfaces properly when more than 10 exist;
*) added QuickSet to RBSXT, RB411, RB711;
*) user manager - command to create and assign user profile from console;
*) added support for LTE modems (cdc ethernet type);
*) fix gre tunnels on x86 and other little endian machines;

It should be fixed, just not listed in changelog.