Question GPU AIO as Intake - A Terrible Idea?

[TM1172]

On a scale of 1-10, 1 being inconceivably stupid and 10 being no big deal, how bad of an idea is having a GPU AIO on the front panel intake of an airflow-intended case, if the CPU is being cooled by an air cooler?

I have an EVGA 3080ti FTW3 Hybrid and a 5900x under a Noctua NH-D15. They are being housed in a Corsair 4000D Airflow case. Currently, the 240mm rad is on top, with a pair of Noctua NF-A12x25's pushing air up out of the case. I have 3x 120mm airflow fans on the front panel providing lots of nice clean air for the case. My problem, however, is that the NH-D15 is so unbelievably large that, with the rad and fans on top exhaust, the heatsink itself won't fit in a front-to-back flow orientation, but only in a bottom-to-top orientation. The heatsink is flush with the GPU rad fans, allowing GPU rad fan rotation, but with only the width of a piece of paper between CPU heatsink and rad fans - the air in the CPU cooler is being sent straight vertically and being dumped directly into about half of the GPU radiator. Now, Noctua included the brackets for this orientation and I've seen vertical CPU coolers before, and my temps are quite good - Prime95 topped out after 1hr30 in Small FFT's at only 77c, and my GPU appears to be handling things ok too.

The main question from line 1 is because I'm wondering about putting that 240mm GPU rad on front as an intake, thus freeing up the CPU heatsink to orient front-to-back. It would allow space for the additional 140mm tower fan for the NH-D15, and I could install an exhaust fan in the back slot to help with nice linear air flow. However, I also know that the 3080ti dumps a simply massive amount of heat, and I'm betting that putting that rad on intake would only heat up the interior of my case, probably negating all the goodness from the linear airflow - not to mention, the added resistance of a radiator slowing down 2/3rds of the intake air. I wouldn't mind someone with more experience than me telling me that this is a stupid idea, because most/all of the videos I've watched and answers I've found have to do only with CPU AIO's, not GPU AIO's. I figure my GPU radiator probably dumps a lot more heat than a CPU AIO would.

Follow-up question, should I be at all concerned about the hot air from the CPU cooler flowing directly (literally directly) into the GPU radiator?

 

[geofelt]

What do you hope to accomplish?
Apparently, all is working well and you have no temperature issues.

NH-D15 works well with just one fan. I might expect 2 degrees difference with two; no big deal.

You have the means to test your proposal, but I would expect no real difference.
Either way, all the cooling air is coming in the front and will eventually exit the case, taking component heat with it.
Your gpu might do a bit better, but the cpu may not.

I would give the proposal a 10, meaning no big deal.
I would not bother.

 

[Phaaze88]

Ahh, amongst all of the cpu AIO/CLC threads, there's one of these in a blue moon.

On a scale of 1-10, 1 being inconceivably stupid and 10 being no big deal, how bad of an idea is having a GPU AIO on the front panel intake of an airflow-intended case, if the CPU is being cooled by an air cooler?

I have an EVGA 3080ti FTW3 Hybrid and a 5900x under a Noctua NH-D15. They are being housed in a Corsair 4000D Airflow case. Currently, the 240mm rad is on top, with a pair of Noctua NF-A12x25's pushing air up out of the case. I have 3x 120mm airflow fans on the front panel providing lots of nice clean air for the case. My problem, however, is that the NH-D15 is so unbelievably large that, with the rad and fans on top exhaust, the heatsink itself won't fit in a front-to-back flow orientation, but only in a bottom-to-top orientation. The heatsink is flush with the GPU rad fans, allowing GPU rad fan rotation, but with only the width of a piece of paper between CPU heatsink and rad fans - the air in the CPU cooler is being sent straight vertically and being dumped directly into about half of the GPU radiator. Now, Noctua included the brackets for this orientation and I've seen vertical CPU coolers before, and my temps are quite good - Prime95 topped out after 1hr30 in Small FFT's at only 77c, and my GPU appears to be handling things ok too.

The main question from line 1 is because I'm wondering about putting that 240mm GPU rad on front as an intake, thus freeing up the CPU heatsink to orient front-to-back. It would allow space for the additional 140mm tower fan for the NH-D15, and I could install an exhaust fan in the back slot to help with nice linear air flow. However, I also know that the 3080ti dumps a simply massive amount of heat, and I'm betting that putting that rad on intake would only heat up the interior of my case, probably negating all the goodness from the linear airflow - not to mention, the added resistance of a radiator slowing down 2/3rds of the intake air. I wouldn't mind someone with more experience than me telling me that this is a stupid idea, because most/all of the videos I've watched and answers I've found have to do only with CPU AIO's, not GPU AIO's. I figure my GPU radiator probably dumps a lot more heat than a CPU AIO would.

Follow-up question, should I be at all concerned about the hot air from the CPU cooler flowing directly (literally directly) into the GPU radiator?

If you have air conditioning, live in an year-long cold climate, or a combo of both, then none of it matters - literally none.
If you do not have these, then there should be a greater focus on enforcing lower power limits to reduce the energy use.
The energy used by the PC disperses into the room, increasing its temperature, and that eventually makes its way back into the PC. One big loop, but air conditioning and cold climates trivialize this cycle.