CPU and Graphics Temperatures vs. Fan activity

[swbruce21]

A few years ago when the ThinkPad T43 came out, it had a hot graphics adaptor so the cooling fan was noisy and running at fairly high rpm all the time. Some guy in Germany wrote a popular little program call TPFanControl which lets the user configure fan rpm in steps as graphics or cpu temperature go up and down. This program over-rides the cooling profile setup in the bios. It responds to the CPU or Graphics temps based on whichever is higher.

My Question: I have a Thinkpad T500 that runs the fan at its minimum level when the computer is doing nothing or when doing common office work. So the fan runs 100% of the time keeping the CPU and GPU at 49c when doing nothing. By using TPFanControl to start the fan at 54c. the fan only runs when some activity increases the cpu or graphics activity, and then it steps to higher rpm's under higher loads.

I have never had a processor or graphics chip fail but I have serviced or replaced a lot of cooling fans.

Setting the fan to start at 54c instead of 49c will cut the fan usage by around 90% over the life of the computer. I have TPFanControl configured to have the BIOS take over fan speeds when the temperature rises above 58c so maximum temps will be managed by the bios profile.

I know the max allowed temperatures for components are much higher that 50-something, but does running components at 54c instead of 49c most of the time make a difference in service life ? I keep my notebooks a long time.

 

[PaulR08]

I would be sure the fan is always running even at 49c, slower but not off. 5 degrees c is not much difference, and don't think it would overheat and fail. Extreme overclocking the cpu without a good fan will shorten the service life much more.

 

[swbruce21]

Can you explain further why you think its good to always have the fan running. processors and power supplies in Desktops get hot real fast without a fan running, so you can never think of runnng without a fan, but components in some notebooks are much closer to being OK without fan. For example, I have 3 old Thinkpad T42's where the fan only runs when the unit is under load. So It seems the only issue in the T500 is if the 5 degrees make difference in the long run. I am not arguing with you, just want more of your thinking on this.

 

[13thmonkey]

There's a possibility that with zero air movement there may be hot spots that are not monitored.
Also you'll find (probably) that the fan will switch off below 54C and on above and it will oscillate on and off (which may be more annoying).
With regards to longevity of the fan, i'd suggest that fans (with a higher start current, than running current) are 'aged' during the startup period, not the running period (maybe at very high speeds too), hence the above oscillation would probably reduce live rather than extend it.

The components standard temp going from 49 to 54 should not be a problem.

 

[swbruce21]

Some good points.

Regarding air circulation . . I have noticed that the keyboard, palm rest and bottom of computer are noticably warm without the fan, even thoght the measured temps of components are only 5c more.

Regarding ocillation off/on. The fan is programmed to go on at 54 and off at 52 so there is not much ocillation.

Regarding startup wear and tear. All the fan failures that I have had have been bearings drying up and starting to bind or make noise. Usually can renew for a while with cleaning and lube.

But all things considered I guess I wil go for the better cooling like you have suggested . . that will cool off the palm rest like it was before.

Thanks

 

[swbruce21]

Best answer selected by swbruce21.

 

[Mousemonkey]

This topic has been closed by Mousemonkey