What's your experience with single vs dual fans on GPUs?

[NewbieOne]

As per title. I'm not exactly great at physics, nor have I ever conducted any proper measurements, but there is something in me that doubts the general belief in the superiority of dual-fan coolers.

Long plate, better dissipation because of more surface to spread the heat on. Then better export through two fans instead of one. This is the theory. But what I've seen in practice with one-, two- and even and three-fan setups is that this is somewhat overrated. I also remember having older cards with one big fan and on a shorter plate and not exactly complaining about the temperature.

I suspect this may be because of the fan size and placement. If the GPU plate is short and the fan is large, the fan covers essentially the whole plate, so whatever heat is generated is removed from the case quickly, or at least from the card.

And for some reason, though I may be wrong (like I said, never was good at physics, or any hard science for that matter), I have more faith in thick 10cm fans (or larger) than something like 2 flimsy 80mm or smaller fanlets that almost feel like plastic foil to the touch.

To some extent tests and reviews seam to disprove my idea, because those two-fan cards do seem to get better temps. I wonder to what extent case layouts and cooling setups matter here.

[King_BR0K]

The older cards you are thinking of probably were lower powered and needed less head dissipation
More fans = same airflow with lower rpm/noise or more airflow with less noise
So it can cool better
In some cases like my gtx 1050ti it is not necessary because the card dose not generate a lot of heat

[NewbieOne]

Well, it depends. Some of them were old units like GeForce 7600GT or Radeon 2600HT (or something), but there was a Radeon 4850 on which I had to put an aftermarket heatsink and afterwards got better results from mounting a single fan in the middle of the card right on top of its processor than two fans left and right with no blades directly above the processor itself.

[_I_]

depends on the card
most cards have enogh cooling for their own needs

i had a passive 8800gt which used the cpu fan to cool it
and wf2 and tf2 cards with dual fans
all have done the job well

[upcoast]

There're many variables like quality of the fans/heatsink and down to the thermal paste application that make the difference. I still have some oldies that are good for their wattage ie GTX280 single fan blower and R9 280x 2 fan cooler.

[C2Dan88]

A GPU cooler is not there just to cool the GPU processor.

The cooler needs to cool the memory chips and VRM's (power circuitry) This is what dual/triple cooler GPU heatsinks are cooling. Each fan can be dedicated to cooling one specific area of the card, a one fan blower cant really do this efficently

With modern GPUs these three ke yareas need to be kept cool to get the best performance out of your GPU to allow for better clock speeds whether your are overclocking the card or not.

When you card starts to gets hot it will throttle, resulting in lower perfermance and you'll see frame drops in your game.

[hawkeye]

Efficiency of fan cooling is dependent on air flow directed at the heated object. Maximum efficiency is obtained with a turbulent air flow. Laminar air flow reduces heeat transfer. So I buy cards with triple fans in the hope that all of the card is covered with turbulent air flow. Counter-rotating fans are more effiicient than those rotating in the same direction..

The rate of heat transfer is also dependent on the difference between the air temperature and hot object. The bigger the difference the more heat transfer. So as blowing cold air is the way to go I leave the side off my cases. The hotter the card, the more cold air is needed, so the more fans are needed.

Then there is blade shape and thickness, fan radios, rotation speed, air flow guides etc that all affect flow.

http://www8.basf.us/PLASTICSWEB/displayanyfile?id=0901a5e180004891

So the way that engineers check cooling performance is to just look up performance specs and reviews.