i thought RB450 was not powerful enough for my office network due to it kept me showing above 80% and often reach 100% of cpu utilization.
i used to connect winbox all the time at work to monitor traffic in real time, but then i found out that winbox caused this issue since if i didn’t connect winbox to the routerboard, the cpu load often below 25% of utilization.
is winbox a resource hog with routerboard RB450?? or is it a bug?? 
if you just log in and do not open any windows - does CPU utilisation increases?
what is traffic throughput of the router?
what firewall, if any
how many queues, if any
is latest version of winbox, is latest version of RouterOS installed on the router, is last RouterBOOT upgrade installed?
with winbox opened without any windows yet, the cpu raised to around 30%, with opening torch, the cpu raised around 50% on average, peak at around 80%.
i’m using winbox 2.2.14 and the latest routeros 3.20 also the latest firmware for the routerboard 450.
what is routerboot? the last time i boot was 10 days ago.
btw, how to set this forum to notify me in email whenever there’s a thread reply since i don’t often check my posting?
thanks in advance. 
Can anybody test this…? I have a similar problem on RB450, cpu goes to 100% even when I`m doing nothing on winbox, I use 3 pppoe clients in diferent ether ports.
Enable Disable mangle rules with no efects on cpu utilization.
I made a new test, is a winbox based bug I guess, I check resources by telnet and the CPU isn`t heavy loaded (same config).
Check it, please.
using the new version of winbox 2.2.14 up from 2.2.13 reduces the cpu utilization to average 50%.
I will test it, and post my experience.
it seems the Tools > Torch which is causing the high cpu utilization on this routerboard. too bad seems torch is quite good tool for monitoring traffic in real time. 
I can confirm as well that it is the torch feature that is using a lot of CPU. Just tested on my home router, a RB450 with a minimal config as a typical home router. 8 filter rules, 1 nat rule.
Basically no traffic: 0-2% CPU
Basically no traffic, winbox opened, no windows: 0-3% CPU
Basically no traffic, winbox opened, torch running: 30-60% CPU
Routing 8Mbps through proxy: 20% CPU
Routing 8Mbps through proxy, winbox opened, no windows: 20% CPU
Routing 8Mbps through proxy, winbox opened, torch running: 60-99% CPU
When routing about 7 Mbps normally though it, it used about 7% CPU without running torch. When starting torch CPU went up to 100% for a little while, and then it gave up and stopped showing anything in torch, and CPU went down again.
I assume this is protect itself from overloading, but it would be nice to notified when this limitation kicks in, or is this just a bug? I saw the same thing happening on an RB1000 when trying to use the torch feature on a interface currently routing a full gigabit.
It would also be nice to know how much traffic one is supposted to be able to torch on each RB model, so one can choose one that is not only capable of rouing the traffic but also effectivly monitoring it with all the great tools available in ROS.
i guess this issue has been solved on v3.27, while using torch, the cpu usage is at its minimum. glad they hear us out.
I am having this same issue on a new RB450G. CPU sits at 6% or so, then I torch a busy Ethernet interface and CPU spikes to 100% and no output data. I had same problems on a RB150.
Thoughts? Happy to provide additional data.
have you tried to upgrade to the latest routeros 3.28 yet? i have no problems with 2 rb450 and 1 rb450g start from routeros v. 3.27 and above.