Is there any way to know what's using CPU cycles on a RouterBoard RB133?

I have one acting as the main router in my house, doing some straight routing onto my work network as well as NAT and DHCP for the home network to connect to the Internet. Sometimes the Internet gets very slow, and when I log on to the RB133, I see that the CPU is pegged in the late 90% range, sometimes even pegged at 100%. This gets so bad that just pinging the router on the Ethernet port sees up to 50% packet loss.

I'm not doing anything particularly complicated on it. It has an R52 radio bridged to one of the Ethernet ports, to act as a wireless router. The radio is in b/g mode, with wpa-psk security, and with adaptive noise immunity set to "none".

The CPU load doesn't seem to be traffic-related. I've watched it while running a speedtest on my PC, which pretty much maxes out its throughput, and CPU stays below 20%.

I'm running out of ideas. Any help?

Should have said: running 3.16. Firmware was 2.12, I've upgraded to 2.18 to see if it helps.

I've found that upgrading the firmware does help alot on the RB1xx boards with v3.x.

However, it is well known that v3.x works like crap on all the RB1xx boards. I used to use them as CPEs when they were available, and in the v2.9.x days it worked like a charm I had maybe 20-30 mangle/queue rules on them for traffic shaping without issue.

Since the v3.x release they still 'work' but are almost useless as the CPU spikes to 90-100% like you mentioned and I even have trouble getting a winbox session to load. I had to remove all the mangle/queue rules and had to shut-off all services except the essentials, just to make them manageable. Once setup I find they seem to work 'OK' but don't stress them at all.

Unfortunately for me I really want the v3.x because of the improvements to the wireless package, otherwise I would be using v2.9.x

I am hoping the v4.x release of RouterOS improves the situation becuase I really don't want to have to replace all the RB1xx I have in operation after only a handful of years.

Cheers

I have good success with RB1xx and ROS3.xx. The solution is to install only the packages that are absolutely necessary and uninstall all others not just disable them. Also, do not install the NTP and usermanager packages. If you need ntp, use the NTP function integrated into the system package.

Thanks for the info, guys. It seems pretty stable so far on the new firmware. I'll try stripping down the packages also.