motherboard and GPU upside down

[froky]

For a very special build I need the motherboard/CPU and GPU positioned upside down. Is there any issues of doing this? Like problem from the fans facing down when running?

 

[LTC8K6]

It shouldn't be a problem as long as airflow is good.

Heat may rise into places where it doesn't normally go, but if airflow through is good, that still shouldn't be a problem.

 

[Anubis]

basically a BTX design was fairly popular a number of years ago

it should be fine

 

[froky]

I tried searching for photos of BTX cases with GPUs connected but found nothing.

Only objection I've heard so far of mounting this way is it causes the hot air to move up (which hot air does) towards the electronics/heatsinks unlike away from them if it was mounted horizontally facing upward.
I don't know if this is a real issue and dangerous or negligible and just a disproven theory people came out with from thinking about basic physics and ignoring other parameters.

 

[LTC8K6]

Graphics cards are mounted that way. It doesn't seem to bother them.

 

[piasabird]

Heat rises so better have some forced front to rear air flow. As long as you have good air flow it should be fine. I cant see a real reason to put a motherboard upside down since it is not designed to be mounted that way.

I think the Intel NUC motherboards have the CPU on the bottom.

I think some laptops run this way also with a hard drive and RAM under the motherboard.

 

[vailr]

Silverstone (?) makes an ATX computer case with the motherboard rotated 90 degrees, so that the I/O ports are located at the top.
If you could provide clearer information on exactly what you're trying to accomplish, there might be some other solutions available.

 

[Cerb]

For a very special build I need the motherboard/CPU and GPU positioned upside down. Is there any issues of doing this? Like problem from the fans facing down when running?

No. There are off the shelf cases that do just that, yet are still ATX, and cool quite well. Since I like its cheaper brother, the Silverstone TJ08-e comes to mind, as an example.

The worst problem you may encounter is the video card sagging enough to touch fins of a big tower heatsink. Prop up the video card, in that case.

Different orientations have been done many times, with custom cases. You can find examples at places like OCN, SPCR, [H], Bit-Tech, etc.. No harm, performance issues, etc.. Everything works fine in basically any orientation.

I tried searching for photos of BTX cases with GPUs connected but found nothing.

Only objection I've heard so far of mounting this way is it causes the hot air to move up (which hot air does) towards the electronics/heatsinks unlike away from them if it was mounted horizontally facing upward.
I don't know if this is a real issue and dangerous or negligible and just a disproven theory people came out with from thinking about basic physics and ignoring other parameters.

With all active cooling, the physics of passive convection cooling won't matter that much, except maybe to a few components on the backside of the motherboard. Most video cards are already upside down, compared to an ideal, "heat rises," orientation...

 

[DigDog]

you dont actually mean UPSIDE DOWN?
as in, with the PCI slots pointing downwards .. towards the ground?

 

[LTC8K6]

you dont actually mean UPSIDE DOWN?
as in, with the PCI slots pointing downwards .. towards the ground?

That's what I assumed.

 

[Ketchup]

HP/Compaq did this for a few years. It never really caught on (you can still find some cases this way), but I always thought it was a good idea. Then again, I thought BTX was a good idea, and look how that turned out!

 

[OlyAR15]

There have been cases that have oriented the motherboard in every conceivable orientation. It seems that any orientation is fine as long as there is sufficient airflow, even when the mb is upside down. I used to have an HTPC based on a silverstone case that inverted the motherboard. Worked fine.

 

[DigDog]

GPUs don't really grab on to the pci slots that well. the retention bolts on the chassis, i've seen them deform both chassis and the clasps of the GPU, and the plastic latch on the pci slot itself is weak at best. i wouldn't mount a GPU dangling downwards ...
but i have never tried it myself.

so try it, for science!

 

[froky]

The PCIE slot *is* going to face downwoards, but *not* the GPU as well, an extension cable is going to be used for connecting to the GPU.

This is for integrating a PC in a complex device, but in a nutshell, this is how the bottom part of the device looks from the inside and why I decided to go the upside down route.

Sure, I could have a second aluminum plate instead of a wire mesh and not have them upside down, and have air flow all around the device, but for some reasons I can't have airtflow holes on the sides of the device's case.

 

[DigDog]

well then, there should be no problem.