Strange behavior was noticed with multicore hardware on platform x86. I tested ROS 5.6 and 5.7. In both cases my x86 router hangs up every 4-6 hours. There is no apparent reason why this is happens: no unusual amount of traffic (about 50 Mbps), no unusual cpu usage (about 50%). It was working about 3 months with multicore configuration and ROS 4.x without any troubles. Router with one core and ROS 5.x working just fine too.
My config consists of simple routing, nat and about 500 simple queues.
Has anybody the same problem?
Thank you.

To avoid misunderstanding: "hangs up" means that router stops to serve clients and become unreachable from the network.

have you set multi-cpu=yes?

have you checked it from local console (keyboard + monitor) when it hangs?

Strange behavior was noticed with multicore hardware on platform x86. I tested ROS 5.6 and 5.7. In both cases my x86 router hangs up every 4-6 hours. There is no apparent reason why this is happens: no unusual amount of traffic (about 50 Mbps), no unusual cpu usage (about 50%). It was working about 3 months with multicore configuration and ROS 4.x without any troubles. Router with one core and ROS 5.x working just fine too.
My config consists of simple routing, nat and about 500 simple queues.
Has anybody the same problem?
Thank you.

Did you restore from a backup in each case. I have had some issues on some systems when restoring. have you tried a system reset-configuration to see if it resolves the problem. also instead of a full backup you can export segments such as /ip firewall export file=firewall from the terminal and then copy these files to your desktop then reset configuration and restore one by one and verify that all is good.

Regards,
Josh

what kind of hdd are you using? ide, usb, sata?

To rodolfo: yes, I checked this option. Without it router cannot even see more than one cpu.

To Chupaka: local console also hangs up and there is no reaction on keyboard input.

To jspool: I didn't used restore from backup. Reboot has usually solved the problem. I'll think about your advice. Thanks.

To changeip: I'm using sata hdd. Is there could be any problem with this?

I had the same sympthoms with my x86 router when i upgraded to 5.x.
I think it worked ok with 5rc10,but later when I upgraded it to 5.2 (or 5.4) it becomes strange.
It was pentium 4 2.8GHz,and it is not real dual core.It's hyperthread.One CPU act like two logical CPUs.RouterOS see it like dual core.When I disabled hyperthreading in bios,all my problems has gone.Maybe you have the same problem.
Cheers,

Ok. I'll check if it could be my case. Thank you.

Thor, this really looks like my problem. Turning off hyperthreading at least made my router working 24 hours without any trouble at the moment. I'm gonna do some tests. I'll write about this later. Thor, thanks a lot

No problem man, Iam glad to help you.

Did your problem with x86 multi core crashing stop after you disable hyper threading?

I have the same problem with dual CPU (2 physical chips) xeon that crashed 2 days after enabling multi-cpu, but hyper threading is enabled.

With multi-cpu=off this same router will run hundreds of days with no crash.

If you have a p4 2.8 with no HT you might as well not enable multi-cpu, because routerOS sees only one anyways.

I want to know if multi-core/multi-cpu with no HT still causes crashing.

Do you ask me or AlexN? If you ask me,my router did not crash even the multi cpu left enabled...but,like i said,it's only one physical core in my case...maybe in your case,multi cpu could also be the problem,don't know....I would like to put core 2 duo cpu in that router,but right now, i don't know will i encounter the same problem with freezing when i do that...it's a remote location and i can't risk freezing....anyone done this without hangs?