Do fans underneath a Graphics Card help? (e.g. on the PSU shroud)

GoogalyMoogaly

GoogalyMoogaly

GoogalyMoogaly

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So I recently got a Lian LI Lancool 216 and since it has the option to mount fan on the PSU shroud I thought I'd give this a go with the hope it would improve GPU cooling and perhaps stop the GPU fans kicking in at idle.
I've tried 3 different sets of fans and have not seen a difference to idle or load temps.
It's a little disappointing. Is anyone using a similar configuration where you have fans under a GPU blowing into the GPU and if so have you noticed an improvement?

My GPU is a Sapphire 7900XT Pulse and I've tried 2 of the following fans:
Silverstone Air Penetrators (SST-AP123)
Corsair Air Series (A1225L12S)
Akasa Apache Blacks
 
i can't see a fan sitting above the psu on the shroud being able to get much in the way of 'clean' air drawn up through the floor of the case - might explain why you're not seeing any great improvements in temps
 
PSU Shroud fans aren't going to move much air regardless, as one is blocked by the PSU anyway, and the other still has to turn air through 90 degrees

Did you try the PCIE Fan Bracket option as well (might work better)?

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A fan at the rear might help pull air more in that direction from the front fan, rather than a lot of it ending up going upwards (especially if you have the front most fan fitted at the top)

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Due to having an AIO cooler I've had to set the case up in the watercooling configuration which prevents attaching the bracket for installing the rear fan.
I was hoping that with the case being designed with this option that the fans (at least the front-most one) would be able to draw in enough air (since the side panel is ventilated).

It's not THE reason I bought the case but I thought it might be nice to try, especially if it would stop my GPU fans from kicking in every few minutes because the GPU exceeds the zero-RPM threshold.
 
I recently added 3 120mm intake fans to the bottom of my case, just under my 9070XT. The PSU is off to the side in a separate chamber, so the fans are pulling air in directly from outside. It hasn’t made any difference to the GPU temperatures during gaming. The only noticeable benefit is some more ARGB lighting…

To be fair the case was already fairly well covered in terms of ventilation, with two intake fans at the front and one exhaust at the back plus 3 on the AIO cooler in the top, so adding 3 more at the bottom was never likely to do much.
 
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Vonhelmet said:
It hasn’t made any difference to the GPU temperatures during gaming.
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prior to putting a waterblock on to my gpu i had it mounted with and without a pair of 120 fans on the bottom and while i can't remember specific numbers i do recall it being significantly cooler with them mounted as not. gpu was vertically mounted in both instances, i only mention in case yours isn't as that might explain the difference in our experiences?

just to add this is an old gpu but the principles should be the same i'd have thought.
 
I did this yesterday, as I had the fans spare, and always wanted to try it, I think it does slightly help my GPU not ramp the fans up as frequently, as it's help direct the air from the 3 140MM intakes directly into the GPU, versus the airflow just blowing straight - at least that's my theory anyway. Either way it can't hurt, and I was bored so they're staying :D:P
 
deviation said:
I did this yesterday, as I had the fans spare, and always wanted to try it, I think it does slightly help my GPU not ramp the fans up as frequently, as it's help direct the air from the 3 140MM intakes directly into the GPU, versus the airflow just blowing straight - at least that's my theory anyway. Either way it can't hurt, and I was bored so they're staying :D:P
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and the next time you're not bored you'll have to remove them to check if the temps rise...ask me how i know?!........this is the way of the pc tinkerer. :cry:
 
Thekwango said:
and the next time you're not bored you'll have to remove them to check if the temps rise...ask me how i know?!........this is the way of the pc tinkerer. :cry:
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:P
It does seem to help, in terms of not ramping the GPU fans as often/hard % wise, temps wise it's basically the same, but for longer - it seems to fluctuate a fair bit less.
The best bit is, they're only 3PIN weak 24.1CFM £5 a fan Arctic P12 Silent Pressure 120MM's - the beauty of that is, I can run them at full whack and only just hear them, so for once a fan lives up to it's 'silent' or 'quiet' name.
I think the reason it is doing something, is it's lifting up the higher CFM airflow from my 3 140MM intakes, into the GPU, so I think my man maths theory has worked :cry: if not, we'll just pretend it has ;):D
 
clone said:
I have 3 140mm phantek d30 fans in the bottom of my phantek nv9 case blowing on my 5090, temps have been fine.
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At this point, you are basically lord of the cooling/temps, aren't you mate :D And you've got that 420MM AIO I want ;)
You're are the reason I'm going to have to buy a new case to fit one:P Stop owning things that I want, you're a terrible influence :cry:
 
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deviation said:
At this point, you are basically lord of the cooling/temps, aren't you mate :D And you've got that 420MM AIO I want ;)
You're are the reason I'm going to have to buy a new case to fit one:P Stop owning things that I want, you're a terrible influence :cry:
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cant go wrong with NV9 plenty of room
 
Well I also tried some Corsair ML120 Elite fans (just trying things I have lying around).
I found those and the Silverstone fans did have some effect if you turned them up high enough. It seems the focused air they produce might have help aim the air at the graphics cards' heatsink. That or maybe they just had a higher top speed.
Either way it did make a bit of difference to the idle temps, but at the speeds they had to spin at they became the loudest fans in the case and I wasn't sure it was worth it just to bring the idle temps of the graphics card down. It would've been far more effective to turn off zero-RPM mode on the GPU and just set the fans to a low rpm instead. The additional fans didn't seem to make much difference to load temps either.
 
GoogalyMoogaly said:
Well I also tried some Corsair ML120 Elite fans (just trying things I have lying around).
I found those and the Silverstone fans did have some effect if you turned them up high enough. It seems the focused air they produce might have help aim the air at the graphics cards' heatsink. That or maybe they just had a higher top speed.
Either way it did make a bit of difference to the idle temps, but at the speeds they had to spin at they became the loudest fans in the case and I wasn't sure it was worth it just to bring the idle temps of the graphics card down. It would've been far more effective to turn off zero-RPM mode on the GPU and just set the fans to a low rpm instead. The additional fans didn't seem to make much difference to load temps either.
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That's why I used very quiet fans running all the time at max rpm ;)
 
In my experience best case airflow is filling front and bottom vents with intake fans and blocking all openings on their mounting panels so air fans push into case has to move thru case and exhaust out back / top vents (with no fans). If openings in intake fan mounting panels are not blocked / sealed some of the air fans are pushing into case leaks thru those holes in front of fans where fans suck back into case where it leaks thru those holes (again). So around and around it goes instead of pushing on thru case.

My case fan (& component fans) never run full speed. In normal use they run about 600rpm making way less noise than room ambient level, so can't hear them. When system works hard like gaming or rendering graphics they speed up to 800-1000rpm becoming audible. Case and component fans run on similar temp to speed curves so as components demand more air case intakes supply it (and a little more because there are more case fans than component fans). This way case fans flow more air into and thru case than components are using allowing case airflow to push components' heated exhaust on out of case. This mean components are supplied air at or very close to room air temp. On new builds I use a cheap indoor/outdoor digital thermometer with wired outdoor sensor positioned in front of component fans to monitor air temp entering components against room air temp. I rarely use case exhaust fans. Last time I did was about 8 years ago.
 
I’ve watched a few videos where they tested different fan configs on my lancool 3 as I was considering sticking some fans under the gpu but adding fans to the bottom never really made much difference, I think so long as you have fans in the front and atleast one in the top/back then adding anymore is just going into diminishing returns and adds more noise than it does cooling power.
 
Joxeon said:
I’ve watched a few videos where they tested different fan configs on my lancool 3 as I was considering sticking some fans under the gpu but adding fans to the bottom never really made much difference, I think so long as you have fans in the front and atleast one in the top/back then adding anymore is just going into diminishing returns and adds more noise than it does cooling power.
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Yeah, that matches what I found.

On a side note, the Lancool 3, that's the one with glass panels on both sides right? I nearly got one of those instead of the Lancool 216.
 
It does help, but it's 100% reliant on the cooling on your GPU as to what type of results you get and it's mostly noise reduction gains rather than performance.

eg. Any of the HUGE 3/4 slot cooling GPU's essentially has enough heatsink cooling capacity where really tiny amounts of airflow from more quiet/better fans under the GPU can have the GPU remain off or running at minimal fan speeds at much higher temps. So you could be playing Baldur's Gate 3 with all settings on for example and the onboard GPU fans doesn't even kick it up from minimal fan speeds (from zero fan mode if it's super hot Summer) or turn it on at all (if only around 19-24C environemental) despite the GPU running a 3440x1440 all Ultra settings display. And during other gaming sessions where it does use the GPU not intensely enough, the onboard fans remain off as the airflow from the fans is enough to keep the GPU cool enough not to need them.

Have a 7900XTX Nitro+ with 3x Noctua A12x25's running at super low speeds in a Lancool 3 (so sort of similar to the Asus Noctua GPUs they made), and something similar in a Antec Flux (Non Pro).
 
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