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-   -   Why are most VGA custom coolers recycling hot air? (http://www.hardwarecanucks.com/forum/air-cooling/24849-why-most-vga-custom-coolers-recycling-hot-air.html)

Skyllz October 27, 2009 05:10 AM

Why are most VGA custom coolers recycling hot air?
 
I've really been wondering and especially with the release again of the 5870 Vapor-X about why are there not more "out of the case exhaust" solution for video cards.

Most if not all "overclocked" version of OEMs are using some cooler that moves the air inside the case, same goes with all aftermarket coolers. In the end, it's raising the ambient temps VS the stock coolers that almost all grab cold air from the bottom of the case and sends the hot air out in the back.

They are overclocking the card, making it run hotter and they release that air in the case... genious. Probably good for benching in open air but in real world situation??

I know you can add other fans in your case to help airflow and all but in the end, I think it's counter productive to release hot air in a case.

I had been looking at alot of cooling solutions got my GTX260s lately to try to quiet them down and other then liquid cooling, I did not find a single cooler that would exhaust the hot air out.

Just a tuesday morning rambling from yours truly.

S.

phil3_66666 October 27, 2009 06:05 AM

I agree with you, but my guest go on: It's much easier for aftermarket compagnie to make cooler without exhaust of the case because the cooler will fit on a lot of card, not only this or this model, also lot of people how change the stock cooling want a quiet one, i never see any exhaust one realy quite...

anyway that my opinion
Phil

sswilson October 27, 2009 06:24 AM

I don't know for sure, but I suspect that the general design of a "closed" shroud (even one that exhausts out the back) may cause extra heat on vid card components which would affect overall overclockability. It's a much smaller area than the interior of a Case and as such would be affected much greater by heat buildup.

MarkOne October 27, 2009 06:33 AM

Since I own a Squeleton, I don't understand the problem

CanadaRox October 27, 2009 09:52 AM

It could be because a standard style fan can create a lot more airflow than a blower style fan can with the same noise. Also blower style coolers like most dual slot GPUs have blow a small amount of air over long fins, so the part closer to the fan is cooler than farther away, but with a regular fan blowing straight down, its spread out more evenly which I'd expect would help keep a more stable temperature. And most of the people who are buying high end GPUs and aftermarket coolers will have a case with good airflow, so the air should be moved out of the case before it gets too hot.

morphy October 27, 2009 03:12 PM

Quote:

Originally Posted by CanadaRox (Post 278034)
It could be because a standard style fan can create a lot more airflow than a blower style fan can with the same airflow. Also blower style coolers like most dual slot GPUs have blow a small amount of air over long fins, so the part closer to the fan is cooler than farther away, but with a regular fan blowing straight down, its spread out more evenly which I'd expect would help keep a more stable temperature. And most of the people who are buying high end GPUs and aftermarket coolers will have a case with good airflow, so the air should be moved out of the case before it gets too hot.

That makes alot of sense. Good explanation as well. +1

Sushi Warrior October 27, 2009 05:03 PM

It gives the vid cards better temps, yet most people don't notice the surrounding temp rises. So people go "OMG IT DROPPED MY TEMPS 1 BAGILLION DEGREES!!!" yet fail to notice it raises CPU temps 5C. Smart on their behalf I guess. Also they would need a custom shroud for every card and not all are the same length or have remotely similar board layouts.

Silvgearx October 27, 2009 06:24 PM

don't most of you own an antec 900/HAF/cm690?

those cases move a crazy amount of air so i really don't see the problem.

ayah October 27, 2009 06:39 PM

Some company needs to make a "new" version of the extinct AC Silencers, with heatpipes and whatnot. Those were awesome, relatively silent and exhausts all the hot air out of the case.
With newer cards like the 58xx, doing that might be a bit tricky.

Surfer_2099 October 27, 2009 09:03 PM

I would venture that the goal of an aftermarket cooler is to:

A- Increase cooling performance
B- Decrease cooler noise
C- Take advantage of different PCB layouts

Now, for A, a larger Heatsink using fins and heatpipes, raising the cooling higher off of the board means that things would have difficulty lining up with any type of rear PCI exhaust system. So from a logistical standpoint, it is preferable to benefit from a bigger, higher cooler and dissipate heat into the case, than it would be to try and reroute the heat out of the case in an effective manner.

For B, a larger Heatsink means a larger fan. A larger fan means lower RPMs and therfore lower fan noise. Also, most aftermarket GPU coolers don't throttle, so you don't have variations in speed. Lastly, most shrouded coolers that exhaust heat outside of the case via the rear have fenestrated grills and a small opening. Right now, take a deep breath and exhale with your mouth wide open. Now, take another deep breath and purse your lips, then exhale. Hear the difference? Now, take a deep breath, purse your lips and place your finger about 2.5cm away from your lips. Now exhale. Hear that crazy amount of noise? That's turbulence and that`s what exhausting heat oou of the back of the case does.

For C, many if not most custom cooled video cards have been redesigned from the PCB up in order to increase voltage, frequencies, etc. Now, I would submit that most coolers are heatsink / fins / large fan combinations. Since that new PCB means the ram and whatnot is not in the same place, it would be cost prohibitive (notwithsanding A and B) to create an effective shrouded, rear exhausting, cooler.

That said... have you ever cranked a rear exhausting cooler to the max? I've got a Gigabye 5850 and on auto, the fan spins quietly at 33% at 100% load, but if I crank that fan to 100%, sure I've now got a hair dryer under my desk, but it cools my card like nobody's buisness.

Anyhow, I was in the mood to answer something while I watched the news so there's my theory.


Cheers!
Conjecture_Canuck :)


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