Question How much do case fans help cooling the graphics card?

[andypouch]

Say I've got a case which is the main stream push / pull configuration with 2 fans at the front as intake and one at the rear for exhaust.



Now that the graphics card is lying horizontally with its base facing up. When it runs, hot air dissipates and rises up towards the roof of the case. So one naturally will fit 1 or 2 fans at the top to further exhaust the hot air out. There are 2 concerns here:



1) Will the 2 fans at the top exhaust more air than the rear one? And furthermore, will air current created by the two fans at the top combine REDUCE the rpm of the rear fan?

2) How effective is this overall arrangement of fans in terms of cooling down the temperature of the graphics card in general?

 

[Gam3r01]

1. Depends on the fans, realistically it dosent matter how you get the heat out as long as it does get out. Generally speaking more fans means you can reduce RPM while keeping airflow up, but most of the time thats something you have to change manually.
2. Again, depends on your current setup and how well its doing. Exhaust is important to have, but chances are intake is more important in most situations. Removing hot air brings ambient temps down slightly, but bringing in fresh, cool air has a far greater effect.

Depending on your case 2x intake and 2x exhaust will probably be the "best" setup (best as in performance for your money), anything more and youll see less difference per fan.

 

[andypouch]

1. Depends on the fans, realistically it dosent matter how you get the heat out as long as it does get out. Generally speaking more fans means you can reduce RPM while keeping airflow up, but most of the time thats something you have to change manually.
2. Again, depends on your current setup and how well its doing. Exhaust is important to have, but chances are intake is more important in most situations. Removing hot air brings ambient temps down slightly, but bringing in fresh, cool air has a far greater effect.

Depending on your case 2x intake and 2x exhaust will probably be the "best" setup (best as in performance for your money), anything more and youll see less difference per fan.

You've spelled out pretty much the same as with many reviews out there, really appreciate.

I just look at the two questions from a common sense point of view and here is what I think:
Say I have 2 at the top and 1 at the rear, if I replace the rear one with an AIO like the Corsair 120mm H60, the rad is in front of the fan closest to the case cutout, the fan is drawing air from inside the case so resulting in pushing the hot air from the rad out. Now we have 2 intake at the front and 2 exhaust at the top. Assuming all 5 fans are identical, then the volume of cold air intake at the front will be the same as the volume exhaust out from the top. And cold air taken in mixes with hot air inside the case resulting in slightly warmer air according to high school physics temp = (M1C1 + M2C2) / (M1+M2). So if I add 1 more intake at the front, would that make the cooling more effective? Your advise.

 

[Gam3r01]

Given your scenario here, adding in an additional front intake, should in theory, reduce temps further (again, to a point, eventually that GPU is going to get all the cold air it can use).
The including of an AIO into the scenario can also have big impacts on GPU temps (or very little). By dumping heat directly outside the case internal case temps will be slightly to moderately lower than a heatsink dumping air inside the case. That being said, a proper intake/exhause setup should get this hot CPU air away from the GPU anyway.

 

[andypouch]

Given your scenario here, adding in an additional front intake, should in theory, reduce temps further (again, to a point, eventually that GPU is going to get all the cold air it can use).
The including of an AIO into the scenario can also have big impacts on GPU temps (or very little). By dumping heat directly outside the case internal case temps will be slightly to moderately lower than a heatsink dumping air inside the case. That being said, a proper intake/exhause setup should get this hot CPU air away from the GPU anyway.

Correct me if I'm wrong, something like the H60 has a advantage over a conventional air cooler is that it eliminates if not completely, most of the heat from the location where the CPU is to wherever else the radiator is located. I have once planned to locate the rad/fan of the AIO at the front. And use the rear as an intake which I believe is quite a novel idea. Furthermore, an air cooler releases heat directly above the CPU which is located between the graphics card and the 2 fans at the top, such arrangement obstructs the two fans pulling heat out.

But then I thought adding 1 more fan at the front as intake will bring in more cold air to mix with the hot air in the case to further reduce the resulting temperature inside the case, so the role of the 3rd fan is as such. However, how effective is this configuration in terms of cooling the graphics card? I wish there was a case out there which opens up the bottom to accommodate 2 more fans to draw air in...

 

[Gam3r01]

Dumping air outside the case is about the only advantage something like an H60 would have, and its not that large of a change in internal temps. However, by moving the air outside the case you effectively starve the VRMs and other motherboard chips of airflow, so it is a trade off.
120mm AIOs are just straight up worse than comparably priced air coolers otherwise.

We see front mounted AIO with rear/top intake quite often, and it generally results in worse temps. Heat rises, and your GPU is blowing air up and around in the case, so it prevents air from reaching downward. Overall airflow is improved by going conventional.

Front intakes are fairly good at lowering GPU temps, so long as the graphics card cooler itself is up to the task.

 

[andypouch]

Your reply is much thoughtful and analytic if I may say so, really appreciate.

Dumping air outside the case is about the only advantage something like an H60 would have, and its not that large of a change in internal temps. However, by moving the air outside the case you effectively starve the VRMs and other motherboard chips of airflow, so it is a trade off.
120mm AIOs are just straight up worse than comparably priced air coolers otherwise.

I see your point about the VRMs and remaining components being starved with cold air when all the good air is pulled out of the case leaving the hot components without air to breathe, this is something I have not thought about before.

Regarding the H60 though, I am using it for my old i5. The chip rose to 60 degree C after overclocking to 3.8 GHz. If I keep holding myself from overclocking the chip, I trust the H60 will continue to do a good job for 4 cores chip, maybe it will fail for 6 or 8 cores chips.

We see front mounted AIO with rear/top intake quite often, and it generally results in worse temps. Heat rises, and your GPU is blowing air up and around in the case, so it prevents air from reaching downward. Overall airflow is improved by going conventional.

Well, about the said configuration I see too many of them in YouTube videos. I doubt if they actually work well and you just confirm my guessing.

Typical configuration is like the whole kit is mounted at the front with the rad behind the fans so the fans are facing out and the rad is inside the case. When the fans start revolving, pulling cold air in, the cold air is mixed with the hot air from the rad and because of the pull resulting warmer air is delivered into the case and joins the hot air radiated from the back of the graphics card. This is where the problem arises. Had it not because of the warm air from the radiator, cold air would have joined the hot air to form the resulting temperature which should theoretically be cooler.

I would more inclined to think that the rad be placed at the top or in the case of CM Q300L, even at the bottom.

You also make a very good point about the recycling of air. Indeed, that's something which require further considerations. As I mentioned above, something like the Q300L is perhaps a better solution as it get perforated front, top and bottom panel which allows air to penetrated through without the filter. And the case must be elevated by some sort of stand instead of placing it on the table so the whole cubic can have air coming through and going out.

Front intakes are fairly good at lowering GPU temps, so long as the graphics card cooler itself is up to the task.

This is the second purpose of this thread, and you sort of confirm my thinking. Though theoretically all the conventional cooling configuration claims their merits of achieving good thermals, but in fact such configuration simply provides the basic needs for heat dissipation of the whole case. Whether they actually capable of cooling the graphics is unknown. no solution!

Better alternative is like what the Bitfenix Prodigy (very old vase) offers, the board lies on a horizontal manner with the graphics board standing vertically. The side panel to the graphics board is perforated, to help pulling cold air from outside right on to the graphics board.

But then, recent years, no such cases are produced.