Keep cpu fan on after pc off

[AllucardCasull]

Is there a way to put some kind of capacitor or battery that is recharged by the PSU in parralel with my cpu fan so it stays on for a minute or 2 after my computer is turned off?

 

[DaveSimmons]

cyberguys.com has something like this in their catalog, but Im not sure whether it's for the CPU fan or a case or PS fan.

 

[stevewm]

I'm still trying to figure out the point of such a device......

Do people really think something like this would affect CPU lifespan in the least bit?

 

[Corporate Thug]

Originally posted by: stevewm
I'm still trying to figure out the point of such a device......

Do people really think something like this would affect CPU lifespan in the least bit?

no

 

[narzy]

Originally posted by: stevewm
I'm still trying to figure out the point of such a device......

Do people really think something like this would affect CPU lifespan in the least bit?

logicly it makes sense, the heat doesn't dissapate immediatly after (aka the instant) you hit the power switch, and having the fan run a little longer to cool it down doesn't sound like such a bad idea. I don't think it would increase the life span, but it would prevent the core from retaining heat after its powered down.

as far as the question, I think I saw the same thing at cyberguys

 

[Insidious]

the actual temperature of the CPU is not normally what limits it's lifetime unless allowed to get very high. it is thermal cycles that create the micro-stresses that tend to "wear out" electronic components. Mitigating the rate of temperature change will actually buy you more protection.

While it may seem counter intuitive, I actually believe you will be better off (theoretically) if you let the CPU cool down slowly.

-Sid

 

[PCMarine]

Keep in mind that safe operating temps (CPU On) are much lower than "storage" temps (CPU Off).

 

[OverVolt]

Uhh... my temps hit 44C while i game, and when i stop it cools down to 30C in like 2seconds.

That bad?

EDIT sry to be a thread stealer I've never heard of such a thing. It would be included with motherboards we buy today if it were important.

 

[butch84]

Im pretty sure the temperature of cpu changes quite rapidly, whereas the heatsink will change temp much more slowly. You dont need to keep a fan running on the heatsink because the cpu (like overvolt says) will cool off very rapidly as it is -

butch

 

[Jhhnn]

Yeh, even though the heatsink temp will rise when the fan stops, the actual processor temp will fall the moment the power is removed... heat is still being transferred to the sink and dissipated, if at a lower rate, which isn't really important, because heat production has ceased....

 

[boyRacer]

Haha... you make your cpu sound like it's a turbo...

I don't think it will be of any use since cpu temp won't generate any more heat after power is turned off... there was a thread about this a loooooong time ago when pcmods came out with their own for like $30 or so. It was pretty trick looking though.

 

[AllucardCasull]

the purpose of this wasnt to make my cpu life longer, its just an idea, and sounds cool, and i dont want to buy anything, im broke as hell. all i wanted to know if there was some way to make that,

 

[narzy]

ya it can be made, I'm not an electronics buff so I couldn't tell you want you needed. (I'm actually a fairly big idiot when it comes to electronic components) and wouldn't know what size capacetor you would need, I would think you would also need a resistor to regulate the power going through the fan. what I would do is get a layout board? can't remember what the damn things are called you use them to lay out your circut before you assemble it. you would have to cut the wire leading from the fan to the motherboard I would do it as close to the middle as possible so you had equal / plenty of room on eather side. place them in the practice board, get the capacitor you'll need (it might be large depending on how much power the fan needs, the capacitor needs to leak that much constantly for 2 minutes) then the resistors to regulate current, then the fan side of the wires into the board. this is a very rough concept of what needs to be done, and you should probably not do it this way. I know nothing about this sort of thing and will probably end up f'ing up your computer if you fallow this advice to the letter. talk to someone who knows what there doing...

one problem I see is charging the capacitor inline with the fan power, by placing the capacitor there, your pulling most likly a considerable amount more power through the wires from the motherboard to the fan, and through the interconnects and circuits that lead to the CPU fan header possibly stressing them (most likely stressing them) beyond their failsafes.

get expert advice before doing this. but it can be done..

sorry for babbling.

 

[narzy]

as far as quick heat dissapation from the core, thats true, however the bottem of the heatsync can stay quite warm (even hot) for a prolonged period of time transfering that heat back and forth from the heatsync, to the heatspreader or core depending on your processor. the current system is fine however, this is just an idea to continue cooling the heatsync and make its job more effective. nothing more. its not to prevent damage, just to give a boost.

 

[Corporate Thug]

Originally posted by: OverVolt
Uhh... my temps hit 44C while i game, and when i stop it cools down to 30C in like 2seconds.

That bad?

EDIT sry to be a thread stealer I've never heard of such a thing. It would be included with motherboards we buy today if it were important.

when gaming your CPU isnt even at 100% load. i have never heard temps jump 14 degrees C

 

[MistaTastyCakes]

Yeah, a lot of CPU's do that.

I run at 40 idle, 56 while gaming.

Nothing wrong with me setup, my heatsink's fan is simply on 7v.

 

[DTSS]

Originally posted by: butch84
Im pretty sure the temperature of cpu changes quite rapidly, whereas the heatsink will change temp much more slowly. You dont need to keep a fan running on the heatsink because the cpu (like overvolt says) will cool off very rapidly as it is -

butch