What is normal operating temperature of RB 450G? According to System Health monitor my RB is 60-65C. Is it normal, or maybe dangerous? There is no special ventilation, but nothing is blocking the vents on the RB box as it stands on a shelf.
I have the same temperature,i just have simple solution for these,buy a cheap 10$ fan and aim it to the 450g 
,gone into 45C.
Mine works around 55-60C without much load. It seems this RB runs a bit to the hot side.
Mine is 68oC in server room… 
mine is not working stable at 800Mhz 
680 Mhz is the factory default speed. I would expect more cooling would be required to work stable at a higher speed.
Atleast overclocking CPU’s for gaming require additional cooling compared to standard CPU speeds. I would also expect overclocked routers would run hotter and be less stable unless you have more cooling.
The temperature sensor is on a hot part of the board, possibly on or underneath the CPU. The temperatures will be higher than the ambient air.
My rb450g is 52 C, but is only running at 1% CPU utilization, I have seen 60-65C before. My router might be sitting on it’s side instead of flat, so there may be more ventilation through the case. If you have it mounted in a case, try taking the cover off to let the heat rise away from the CPU easier. If if not in a case, add a fan if you think it is too warm, but I wouldn’t worry unless you were seeing 70C or the router was crashing. If the router is not using the CPU Load at 60-100%, you can try a lower frequency to underclock it and lower the heat generated by the CPU slightly.
I think I would worry and actually worry a lot since the RB450G is suppose to work up to 45C according to this:
http://routerboard.com/pricelist.php?showProduct=52
It is not very clear though if that is the ambient air temp in the box or the sensor’s temp and where the sensor is located at. However, even if we assume the sensor’s location is inside the CPU, 55-60C is still a pretty high temp to run without any load whatsoever.
I am replacing one of these with a dual core soon. Load is too high, speeeds in Bulgaria are reaching the top limits.
On one of these, I have cut off the space from above, I “glued” it to the bottom of a shelf. Its running at 60C right now but in hot summer I would add a 12v fan that I cut off of a cheapo chinese atx psu. If I have time I could even experiment with 800MHz.
Another one I “glued” to the side. Its running 55C. Will see what will happen in hot summer.
I need to check the capacitors if they are “bad-caps”.
I believe this is operational temperature - so this numbers are for environment outside the router. I don’t think that -20C is possible inside the 450G without any additional cooling
I have placed near RB 450G 60mm fan from old PC case, connected it to the old 5V power supply, so it runs slowly and quiet.
Now System Health shows 42-45C, that is way better then up to 69C without cooling One serious disadvantage - it is better not to blind-touch the RB450G, because of the open fan
I noticed that my RB450G is running at a temp of 92 degrees 
and a voltage of 13.3 Volt
Some info from mine rb450g
[guest@RB450G] /system health> print
voltage: 22.5V
temperature: 51C
[guest@RB450G] /system> resource print
uptime: 2d12h18m45s
version: 5.4
free-memory: 240180KiB
total-memory: 257120KiB
cpu: MIPS 24Kc V7.4
cpu-count: 1
cpu-frequency: 400MHz
cpu-load: 1%
free-hdd-space: 471396KiB
total-hdd-space: 520192KiB
write-sect-since-reboot: 10122
write-sect-total: 156588
bad-blocks: 1.3%
architecture-name: mipsbe
board-name: RB450G
platform: MikroTik
[guest@RB450G] /system>
As you can see, ~51° in the middle of summer (room temp around 28-30°), with CPU frequency reduced to 400 MHz.
Put outside of bedroom/office with additional cooling fan
that’s the outdoor air temperature, not the board temperature!
At what RB4xx temperature sensor reading do we need to set our Nagios alarms?
I have one unit mounted in a box in a field with no trees which is seeing readings of 80 C for two or three hours in the afternoon. I am going to try to build the equipment enclosure some shade.
did you see any problems at the 80C temperature reading?
the temperature sensor is not very accurate so do not trust only that.
If I replace the poweradapter 24v with a 12v one, should that decrease the temperature?
With 24v it’s now: 24,5 Volt 61 C
So, no “rules of thumb?” 10% margin of error? 30% margin of error? 10% margin at 20C, 60% margin at 25C, to be ridiculous?
I have not seen errors which I could attribute to the mikrotik showing a temperature of 80C. Once the days got warm enough that the Mikrotik spent a couple of hours at that temperature, the 12v DC - 120v AC inverter in the same box began shutting down due to thermal issues.
Unfortunately, the mikrotik is the only thermal sensor I have in many locations.
some more intersting info
This router is so important, I cant even down it for a minute and we get in trouble with the banks voip, waiting in christmas to replace it sometime
just noticed this now on the 450g, cpu peaks to 100% easily at times, pushes around 3M of g729 voip thru with around 30M of data concurrently, i see no issues so far on it, but growing pains would require upgrade soon i guess 
cpu-used: 89
free-memory: 222076
voltage: 21.7V
temperature: 82C
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