Help me school some n00bs.

D

Doward

[H]ard|Gawd
Joined
Jul 3, 2004
Messages
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Ok, I'm in an arguement with a room full of newbies here, over cooling a computer.

Newbie A is claiming his cpu is COLDER than ambient temperature, using air cooling only - no water cooling, no nothing.

Other newbies agreeing.

Possible?

Thermodynamics tells me that you simply CAN NOT cool anything via air, any cooler than the air itself is.

So what's the scoop here? Am I right?
 
People are idiots. I guess there is some endothermic reaction going on in his chip.
 
Absolutely impossible, unless the chip was chilled prior to installation and it hasn't been turned on and hasn't been out of the freezer long enough to warm up to room temperature.
 
ask him what he cools his flux capacitor with? :p
yeah their bs is thick and heavy
 
Slartibartfast said:
Sounds like he is reading his cpu temp in F when it's in C...
Click to expand...
LOL

I once told my friend that my chip idled at 32. He flipped out. 'Dude, I swear - mine sits a 97! What should I do!?'
 
I'm an idiot and i even know something that PUTS OUT HEAT can NOT run cooler then ambient temp especially around OTHER parts that PUT OUT HEAT as well which all btw started out at NO lower then ambient BEFORE starting to put heat out once turned on! ;)
 
Tell him to prove it to you by bringing the rig in. Then expose him in front of all the dupes. :cool:
 
I might do that :D

I'm going to show him this thread tomorrow when we come in to the shop ;)
 
People have crazy ideas about thermodynamics.

Wind chill is a big one that many people simply can't get their head around. It feels colder when the wind is blowing, so it must actually make objects colder than they would be without the wind blowing, right?

Well, only if they're above the air temperature. The wind action simply speeds up the process of heat loss. See, heat travels from areas of higher heat to areas of lower heat. Your body will lose its heat to the air faster when the wind is blowing than when the wind is not blowing, so it feels colder.

A CPU will lose its heat to the ambient air faster when there is air blowing over it than when there is not.. this is why we have fans on our heatsinks.

However, no matter how hard the air blows, it can only move away the CPU's excess heat faster. If you turn the CPU off but leave the fan on, the CPU itself will equalize with ambient temperature faster than if the fan were off as well... but the CPU will never get colder than the air temperature. Once the temperatures are equal, there is no more movement of heat.

You would have use an object or liquid or gas colder than ambient air temperature to absorb enough heat from the CPU for its temperature to drop below ambient. A Peltier can do this, because the surface that mates to the CPU gets significantly colder than the air. A chilled water setup *could* do this, but you'd have condensation inside the case.

A regular water setup *cannot* do this, because the water itself is never below ambient temperatures (unless you were dumb and tossed ice in).
 
such idiotic remarks are easily rebutted with one word:
how
when they say magic, you have won.
 
Yeah, just like this friend of mine with an Engineering Sample of a C2D 6800 extreme. He says he's sitting at 5.1ghz on air and that, "he's run a chip so hot it soldered it's self to the socket"

I hate people desu :(
 
Doward said:
Newbie A is claiming his cpu is COLDER than ambient temperature, using "I am full of hot air cooling" only - no water cooling, no nothing.
Click to expand...
Fixed for the benefit of Newbie A, in other words he is full of BS... *LOL* maybe if he built some kind of ductwork and his "air cooling" is his AC on high blowing directly over his heatsink.......
 
Ask him where he is getting his lower than ambient readings from. If he tells you from the bios or simply from what the computer quotes him then he is oblivious that most mb's have improperly place thermistors on motherboards. Even so, it still shouldn't read below amibent. The thermistors ARE accurate for the location they are in, don't get me wrong, they are just not accurate for what they are supposed to be reporting (CPU in this case). Power mosfet thermistors are usually correct in their reports becase they are correctly placed there in my testing on 3 boards, but many times they put the cpu thermistors right at the same location reporting outrageous high cpu temps. In all circumstance there will never be a case where it's lower than ambient w/o Peltier, Gas compression, or dry ice.

Maybe this is his problem: My dfi reports 8c lower than actual until I go into bios and correct it. I know it's wrong, I've tested it. I think in this case I may have got a degree or 2 below ambient before the adjustment. Coretemp reports lower then ambient temps and is not accurate until it starts kick out readings above 45c. Then coretemp actually starts giving you true numbers. I know some will dispute me about this but yes, I've tested that program too.
 
you can not achieve temps cooler than ambient temp without water cooling...unless your temp sensors are confused :D

 
well strictly speaking you can't achieve temps cooler than ambient WITH water cooling either...

that is with 'standard' watercooling (without chilling it)
 
Who knows where he is getting his temperature from. Some motherboards might have a wrong way of calculating the temperature of the cpu. On mine, with a northwood core, the idle temperature in windows is 25C, the case temperature is 40C. If I pop in a prescott, the idle cpu temperature jumps to 45C. I am using water cooling. As for air cooled temperatures, I remember the northwood was around 35C and the prescott was at 60C. I know the northwoods run cool, but it's not that cool.

Oh yeah, room ambient temperature is usually around 25C plus or minus 3C.
 
Ha.. well, I'll let him read this up. He'll probably deny the whole thing, though :D
 
Doward said:
Ok, I'm in an arguement with a room full of newbies here, over cooling a computer.

Newbie A is claiming his cpu is COLDER than ambient temperature, using air cooling only - no water cooling, no nothing.

Other newbies agreeing.

Possible?

Thermodynamics tells me that you simply CAN NOT cool anything via air, any cooler than the air itself is.

So what's the scoop here? Am I right?
Click to expand...

I dun kno if any1 relized this but that right there shoulda been enuff to stifle him. When you spout laws of Thermodynamics that can be proven at someone, usually, their wrong.
 
Doward said:
Ok, I'm in an arguement with a room full of newbies here, over cooling a computer.

Newbie A is claiming his cpu is COLDER than ambient temperature, using air cooling only - no water cooling, no nothing.

Other newbies agreeing.

Possible?

Thermodynamics tells me that you simply CAN NOT cool anything via air, any cooler than the air itself is.

So what's the scoop here? Am I right?
Click to expand...
I would not waste my time arguing with them... let them wallow in their ignorance.
 
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