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CPU stock fan and speed issue

I'm trying to problem solve an issue with my PC suddenly turning off
Initially I thought it was maybe the video card but now edging to the CPU
Running SpeedFan no matter the CPU temperature (going up to 70 degrees) the reported fan speed always hovers around 800-900 RPM and never more

First question - is SpeedFan reliable?
Second questions - how to solve?

The fan is plugged into the correct jumper on the MB and is a stock Intel heatsink
I'm not running intensive stuff like the latest games, just web work so mysql queries, watching videos etc so the temperature the CPU is running at it a bit worrying - everything in the case was bought new in the past year or so (bar the video card which is about 10 years old!)
Gonna reseat the CPU tomorrow with fresh thermal paste

This has only started happening the past few weeks or so with no changes in use

Even the chassis fans never go over 1000 rpm
Avatar of Ramin

800-900 RPM is not enough for CPU fan.
replace the fan.
Fans normally run low or high and only run if it is needed. It is a result of your problem, not a cause

Given you are prepared to re-seat, do re-seat both CPU and GPU. Use top quality thermal paste (Arctic Silver, say), use a thin, even layer, re-seat and test.

Upon startup look at Task Manager, sort by CPU  and see if anything sticks out as running when it should not,
If the CPU is getting up to 70 degrees and the CPU fan speed is not increasing, that sounds like the pulse-width modulation ("PWM") for the CPU fan is not working correctly.

CPU fans on all recent motherboards are four-wire fans - DC, ground, PWM input and tach output.  The PWM input allows continuous control over fan speed from minimum to maximum.  Default PWM is supplied by the motherboard and PWM can also be controlled by the operating system.  If your system is BIOS and not UEFI, check the BIOS settings ensure that fan speed control is enabled.

Before going to the extent of re-greasing the CPU, you might swap the CPU fan with another identical unit and see if the problem goes away.

Also make sure that the CPU fan is plugged into the CPU fan connector on the motherboard, not some other fan connector.  Many motherboards have multiple fan connectors but only one is for the CPU fan.
if changing the CPU fan didn't solve the problem then,
Buy a (Arctic Silver, say) as John mentioned, thermal paste ( also check expiry date), apply it using the link below, place the fan on cpu, connect it's connector to mainboard and test.
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Yes i agree sub 1000 rpm all the time doesn't seem right and no change no matter the temperature is even weirder
Even more weird my CPU has now been running about about 40 degrees with an high usage due to a large DB to DB conversion going on for the past hour
But you know how it is - the minute you walk away and not watching it all goes wrong

The fan is connected to the right connector
Even the chassis fans never go over 1000 rpm
it must be something like 1500~2500
You should get the manufacturer's specifications on fan speeds. Different machines will have different fans. If all your fans are below 1000 rpm, that is either by design, or there is a more significant issue.
please download this program, install it, run it and post the result here.
Max rpm on the rear fan is 1200, it's an older Cooler Master Case

Already tried OHM before and got rid of it - CPU fan speed goes from 0 to 3500 over the course of seconds constantly but tends to hover mainly around 900
Also report CPU temp at about 10 degrees higher than speedfan
Okay, check the CPU temperature from BIOS please,
Will have to wait for that got 2 hours left on a db data conversion happening
Okay, no problem ...
Maybe this will help solve the problem - my MB

Will have to look into the Fan Xpert more
yes, try to change/disable Fan xpert settings from BIOS,

Fan Xpert
ASUS Fan Xpert intelligently allows users to adjust both the CPU and chassis fan speed according to different ambient temperature , which is caused by different climate conditions in different geographic regions and system loading.Built-in variety of useful profiles offer flexible controls of fan speed to achieve a quiet and cool environment.

also disable AI Nap and check if it helps.

find the best combination of Fan Xpert and AI Nap setting (on/off)  to have a quiet but efficient fan.
Did you apply thermal paste
what cpu do you have?   the max temp is different for all models
also - if replacing the fan does not solve it, you may have a motherboard problem
try also to update the bios - that often has an update for the cpu fan, or newer cpu's
Intel "factory" heatsinks in my experience are usually pretty good. It is in Intel's best interest not to have CPUs overheat and die.

If you are running the CPU at its rated clock speed and voltage and don't need the machine to be near silent, the stock fan and heatsink should be fine. If you are in a an unusually dusty environment, you may need to blow the dust out once a year or so. Other than that, the stock Intel fans usually last decades.
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Well running now 2 hours, doing the same stuff as yesterday that was taking the CPU over 60 degrees - so far its hardly even going over 40 and the fan is barely moving

Will have to run for a few days to see if this fixes the sudden shut downs but very happy with the new fan even though it's PITA to install

Not sure how to distribute points/best answer
You ended up replacing thermal compound and the fan. Distribute points as you see best.
assign the points to yourself - since you supposed that could be the cause
Was what I suspected