Would a aftermarket cooler keep your room cooler or not? *poll*

[silkstone]

I ran my own bitcoin farm and helped with a large scale op, hot/cold aisle arrangement.

I was mistaken though, more qualified people are here.

B.Sc Physics with Astrophysics here. Also a PGCE and a few years teaching this crap. I'm no expert, but I know enough.

A couple of people commented that the CPU will draw less power doing the same task if it's cooler (ie it will be more efficient). I figure they measured it?

If so, not by a much, especially if the voltage is CPU voltage is kept constant.

If anything, resistance increases with temp, and current goes down so less power draw at higher temps. Though CPUs are not anything like Ohmic, so I'm not really sure.

 

[infrared]

A couple of people commented that the CPU will draw less power doing the same task if it's cooler (ie it will be more efficient). I figure they measured it?

Yep, I have my pc plugged into a wattmeter permanently so i can keep an eye on what's going on. I don't really have enough rad area in my loop, so i run the fans a bit higher during the day which keeps coolant ~36c, and at night i turn the fans down a bit which results in 40c, that extra 5-6c (on-chip temps actually rise a little more than the coolant) Now on my typical arrangement with both cards undervolted slightly to 1.1v @ 1ghz and cpu running 4.5ghz 1.37v it normally uses around 630w with fans cranked up and with fans in slightly less irritating mode it rises to about 660w after the coolant has finished warming up. In fact if you turn the fans off completely to heat the loop fast you can see the wattage rising quite easily. The difference is mostly across the GPU's, the cpu does rise by 2-3w according to AIDA64.

It's a very small difference, not really enough to be relevant to the thread, but it's a real thing so I don't want people that are correct being told they're wrong kinda thing

sorry for edits, wasn't quite happy with a few thinngs

 

[phanbuey]

I think this thread was massively overcomplicated...

 

[infrared]

Yes, definitely! There's been some interesting posts though so it's not all bad

 

[CAPSLOCKSTUCK]

Im only reading it cos im totally bored.

 

[Steevo]

Its not overcomplicated, the question asked was perhaps not what the OP really meant to ask, and either way if OP understands that just like all else in physics, what you put in is what has to come out, we have explained everything we needed to.

 

[rruff]

If anything, resistance increases with temp, and current goes down so less power draw at higher temps. Though CPUs are not anything like Ohmic, so I'm not really sure.

Resistance goes up but power consumption will depend on what the CPU needs to hit the same clocks. I'm guessing it's current, so if R goes up, then so does V at the same clocks.

 

[Air]

Yep, I have my pc plugged into a wattmeter permanently so i can keep an eye on what's going on. I don't really have enough rad area in my loop, so i run the fans a bit higher during the day which keeps coolant ~36c, and at night i turn the fans down a bit which results in 40c, that extra 5-6c (on-chip temps actually rise a little more than the coolant) Now on my typical arrangement with both cards undervolted slightly to 1.1v @ 1ghz and cpu running 4.5ghz 1.37v it normally uses around 630w with fans cranked up and with fans in slightly less irritating mode it rises to about 660w after the coolant has finished warming up. In fact if you turn the fans off completely to heat the loop fast you can see the wattage rising quite easily. The difference is mostly across the GPU's, the cpu does rise by 2-3w according to AIDA64.

It's a very small difference, not really enough to be relevant to the thread, but it's a real thing so I don't want people that are correct being told they're wrong kinda thing

sorry for edits, wasn't quite happy with a few thinngs

Thanks for the info. This thread was in need of some actual data. And yeah, as i said, negligible difference.

 

[jboydgolfer]

Im only reading it cos im totally bored.

I'm surprised you haven't posted a thread on that rotten egg nebula that's normally or type a thing

 

[Agentbb007]

When gaming if I up the fans on my NZXT Kraken X61 it makes my room hotter. I guess more heat is trapped in my case and radiator when the fan speed is lower. When I raise the fan speed it pushes more of that warm air into my room.

 

[CAPSLOCKSTUCK]

What rotten egg nebula?
You mean the one that the erroneous voters got on their faces?

 

[infrared]

Thanks for the info. This thread was in need of some actual data.

No prob, although I'm slightly moderately concerned at how intimately i know this machine now!!!

Honestly though, I would have expected what silkstone predicted with ohms law if I hadn't observed this myself.

I just had a looksee at what google reckoned about it because I'm procrastinating instead of sleeping lol... this is kinda interesting tidbit i thought.

Why does the conductivity of a semiconductor increases with increasing temperature?
The electrical conductivity of a semiconductor increases with increase in temperature because with increase in temperature the electrons overcome the energy barrier between the valence band and the conduction band easily.

 

[EarthDog]

Just to throw a wrench in the spokes... are you sure whatever stress test you are running is a constant load??? Most are not.

Regardless, power use does change with temps, but VERY little. Not enough to make this poor beaten horse get up again for another beating.. lol!

 

[infrared]

No that's cool, I don't mind looking for holes in this, I might have gone awry somewhere.
And no, it's not scientific by any means, i could try to log it properly but I'm not sure it's interesting enough to bother with but it's easy to screenshot the afterburner graph showing the gpu wattages, would have to do it tomorrow now though. I was just watching it while it was only folding and crunching with nothing else going on in the background, cpu was at a fairly stead 95%, it was on the same work units while I was watching, all tasks hours left to run and i watched this over about 5-10 mins, not too long. The wattage was holding steady other than creeping slowly.

Ah I keep forgetting all this is popping up notifications for everyone again! Yep agreed, it's a completely negligible amount.

edit: could also be the VRM's contributing to extra wattage at the wall too I wonder. Meh. idk. Going to bed lol. Laters TPU!

 

[dorsetknob]

What rotten egg nebula?
You mean the one that the erroneous voters got on their faces?

 

[jboydgolfer]

What rotten egg nebula?
You mean the one that the erroneous voters got on their faces?

I'm sorry I actually meant to say the calabash nebula. Since NASA actually caught the initial explosion which is a rare event to catch on film.

https://www.google.com/amp/kfor.com/2017/02/13/nasa-captures-rare-shot-of-a-star-in-mid-death/amp/


But I digress as it's severely off topic

 

[Solaris17]

Side note** If you are personally past measuring how much your P4 makes your balls sweat with a hyper 212 vs a stock HS when playing battlefield 4 and your interested in thermodynamics you should check out the heat death of the universe if you havn't already.

https://en.wikipedia.org/wiki/Heat_death_of_the_universe

 

[silkstone]

No prob, although I'm slightly moderately concerned at how intimately i know this machine now!!!

Honestly though, I would have expected what silkstone predicted with ohms law if I hadn't observed this myself.

I just had a looksee at what google reckoned about it because I'm procrastinating instead of sleeping lol... this is kinda interesting tidbit i thought.

Why does the conductivity of a semiconductor increases with increasing temperature?
The electrical conductivity of a semiconductor increases with increase in temperature because with increase in temperature the electrons overcome the energy barrier between the valence band and the conduction band easily.

Thanks. It's nice to learn new things, I didn't have time to look it up before work this morning but that makes sense. It also explains why temperature, rather than voltage, of CPUs is the killer.

Now we just need a material scientist to pop in and tell us what the typical change in conductivity would be from 40 - 80 degrees.

 

[hat]

I must admit, I never thought this thread would go on this long...

 

[Mussels]

A couple of people commented that the CPU will draw less power doing the same task if it's cooler (ie it will be more efficient). I figure they measured it?

its very small scale, but its well known basic science. the 5 watts people mentioned is probably an extreme amount - if you take 20C off a stock clocked CPU you might only take 1W off the power consumption/total heat generated.

 

[Steevo]

Silicon has a runaway effect, its greater than exponential once you are past "the bend of the knee" I believe, but it takes a lot more heat than the chip is designed to run at before throttling or shutting down before the runaway is reached. I once cleaned my old, old, old PC and forgot to plug in my CPU fan, and the CPU managed to boot windows and run for about 30 more seconds before it thermally tripped and shut down. I burned my fingers on the heatsink, and it left burns. But a minute later I powered it on and it was fine, and the sheer number of computers in death ovens back in the day (computer desk with tower inside with no vents, minus a few cord cutouts) that survived proves silicon is fine being hot, its the rest of the stuff that doesn't like it. Power traces in the motherboard, voltage regulators, capacitors, plastics.....

 

[infrared]

I decided to test this a bit more carefully..
Both screenshots were after 15s of full CPU load, Folding@home was paused, and WCG set to use 100% CPU. The screenshots are only about 5 minutes apart so the same work units were running for both. It's actually a more stable load than prime95 and a real world load so figured I'd stick to this instead of a benchmark/stress test.

+7W on the 6700k when i bring coolant from 25c to 45c. I can't be bothered to test it but I'm sure running stock clocks/volts the increase would be much less as Mussels said.

 

[Mussels]

+7W on the 6700k when i bring coolant from 25c to 45c. I can't be bothered to test it but I'm sure running stock clocks/volts the increase would be much less as Mussels said.

View attachment 84055

would you look at that, an educated guess based on the science was pretty close to the mark.

 

[TheBurn]

Errrr....

So we aren't testing within a vacuum, and the fact of you being in the room increasing the ambient temp; its a measurement of the temp overall in the household room or gamers room. with you and the gaming computer powered on within it. There is some ambient air temp change in the room affected by a window, or door where air escapes or enters the environment.

So a larger CPU heatsink will hold more heat and dissipates less heat then its lower mass counterpart This is the essential design of top quality heatsinks.
A WC heatsink transfers heat from the block, but via tubing and water, exiting via the radiator essentially in its design.
The normal user can measure the air temperature dissipated from the fan exhausts of the pc case. And there would be a significant difference thats measurable using a large heatsink, versus smaller passive/or active heatsink, versus WC system. And this effects ambient air temperature in the room; how would it not ?

So if the aftermarket(larger and better designed) cooler can contain more heatmass and dissipate less heat, then the case temp and room ambient temp changes less over time.

Where is the wrong?

 

[infrared]

Errrr....

So we aren't testing within a vacuum, its a standard household room or gamers room. There is some ambient air temp change in the room affected by a window, or door where air escapes or enters the environment.

So a larger CPU heatsink will hold more heat and dissipates less heat then its lower mass counterpart This is the essential design of top quality heatsinks.
A WC heatsink transfers heat from the block, but via tubing and water, exiting via the radiator essentially in its design.
A heatsink isn't designed to 'hold' heat, it is designed to dissipate it. And it will only dissipate however much heat the cpu is outputting.

The normal user can measure the air temperature dissipated from the fan exhausts of the pc case. And there would be a significant difference thats measurable using a large heatsink, versus smaller passive heatsink, versus WC system. And this effects ambient air temperature in the room; how would it not ?
A passive heatsink has less airflow, so to remove the same heat it is expected that the slower exhaust you measure will be warmer than if there was a lot of airflow. This doesn't have any effect at all on the total heat that is entering the room. It's just more or less diluted if that analogy makes sense.

So if the aftermarket(larger and better designed) cooler can contain more heatmass and dissipate less heat, then the case temp and room ambient temp changes less over time.

Where is the wrong?

There you go, hope that makes sense to you. (click expand, i highlighted my bits in blue)