[SOLVED] Be Quiet! Silent Base 802 - normal or inverted for optimal GPU airflow?

[hyperreal]

Hi all,

I have a very specific use case which is why I also have very specific needs for a PC case. I have broken the post down into sections, I hope it's helpful.
I'm a fairly experienced builder, but my current PC is the first one where the components generate a significant amount of heat, so I'm quite new to airflow optimization. Also, note that some of the questions might rise from my own anxiety and perfectionism rather than actual thermal issues.

TL;DR: What's the best way to optimize airflow to the GPU in the be quiet! Silent Base 802 when using the mesh panels?

Premise
I'm planning to rebuild my aging system into a new case in the hopes of decreasing noise levels. I'm very close to getting the be quiet! Silent Base 802. I've done a lot of research and the only possible issue I might have with the case is the GPU temperature.
I have an MSI GTX 980 Ti 6 Gb gaming edition that I bought used in 2019. It performs well but I'm often hesitant to run it at full power because of the very noisy fans it has. The included MSI cooler is very effective but becomes quite loud at 70% speed and annoingly loud at 80%. To alleviate this, I have added a 140mm intake fan to the side panel to provide the GPU with fresh air and this allows me to keep the fans at about 65% max when gaming at 1080p and maybe taking graphics settings down just a notch from what the GPU is capable of. With this setup, the GPU core temperature rarely goes above +75 degrees Celsius. The card can safely be pushed to at least +83 and even above, but as I said, I don't feel comfortable doing it.

Use case
I also use the same PC for hobbyist/pro-amateur music production, sound design and audio post-production. In that context, any noise reduction is good and I very much like the idea of easily switchable panels emphasizing either soundproofing or higher airflow at the cost of decreased thermal performance or increased noise levels, respectively. Running a DAW is mostly CPU-intensive work, so whenever using the soundproof panels, I wouldn't have to worry about GPU thermals. Also, my CPU runs relatively cool, so any thermal increase there would probably be within acceptable limits.
On the gaming side of things, my hope is to avoid excessive long-term thermal strain and also minimize thermal buildup inside the new case. Fan noise is not as big of an issue here as I use headphones when gaming. But still something I wouldn't mind improving if possible.
I will be of course using the mesh panels when gaming. I'll also be changing the thermal paste on the GPU if can build up the courage to mess with a pre-built GPU assembly.

Possible problems & solutions
Judging by many of the reviews, in the default layout the GPU seems to be the worst thermal hotspot even when using the mesh panels, although in one experiment this was solved simply by moving one of the included front fans to a top exhaust position. Would it be beneficial to keep both front fans to maximize intake but still add a top exhaust? In another review, adding an intake to the fan slot in the PSU shroud near the front actually worsened GPU thermals. Should I look into adding a bottom intake fan to an "unofficial" location further down the PSU shroud, below the GPU?

An alternative solution would be to use the inverted layout. In that configuration I could add a top fan as an intake, providing fresh air for the GPU. It could even be better than a side fan since the top intake would be blowing into the same direction as the GPU fans. However, I'm concerned about possible thermal buildup and/or airflow disruption, as in this layout the only exhaust fan would be located in the lower corner. Could this be an issue and should I look into adding a third front fan to secure more airflow from front to back?
I can add only one top fan because I'm planning to use both of the included panels. The closed panel set features a separate, ventilated piece for the rearmost top fan.

In either configuration I'd like to aim for neutral or positive pressure to avoid unnecessary dust buildup.



Any tips and experiences with this case would be appreciated!

TL;DR: What's the best way to optimize airflow to the GPU in the be quiet! Silent Base 802 when using the mesh panels?
---
System specs:
ASUS Z170-A motherboard (2015)
Intel i5 6600K (2015) w/ Cooler Master Hyper Tx3 EVO
MSI GTX 980 Ti 6 Gb gaming edition w/ original dual fan cooler (second-hand from 2019, original purchase date unknown)
2x8 Gb Kingston HyperX Fury DDR4 2400 MHz (2020)
3x Samsung SSDs (OS disk from 2015, other two from 2020)
Corsair TX650 PSU (from 2011, unused and in storage until 2015).
Built into a Fractal Design Core 3300 with the stock case fans (1x intake front, 1x exhaust back) and an added Noctua 140mm intake fan attached to the side panel.

Ambient temperature: Varying from +28 C in the summer to +22 C during the coldest winter months.
Current noise levels: About 42 dB average in idle. 46 dB average if running the GPU fans at 80%. Measured with an iPhone app, so not necessarily accurate.

Other cases I have researched include the Define 7 and Meshify 2 by Fractal (both very good options but won't deliver the 2-in-1 solution) and the Phanteks P600S (same principle but I prefer Be Quiet's front panel design)

 

[Lutfij]

Welcome to the forums, newcomer!

I'd say keep the layout in the normal position. If you've got time on your hands and are willing to undergo trial and error, you can try an inverted layout as well. I'd see the inverted layout ideal for watercooling mind you, since you can transport heat to your radiator where the heat is dissipated. For an aircooling system, the heat will naturally rise to the top where it's evacuated with convection currents or a fan set to exhaust.

As for your inverted experiment, cold air will always be found at the bottom of any stack, since cooler air is denser and heavier while hot air is lighter and will naturally move to the top. In essence you're going to be stagnating the heat in the case. Out of curiosity, what fans do you have to work with? If it's those 3 fans listed, I'd remove the side panel fan and have fans at the front, then the rear and top. That way the front fans will draw in cooler ambient air and the top and rear will aid in exhaust.

 

[hyperreal]

Welcome to the forums, newcomer!

Thanks, and thank you for the quick reply.

For an aircooling system, the heat will naturally rise to the top where it's evacuated with convection currents or a fan set to exhaust.

As for your inverted experiment, cold air will always be found at the bottom of any stack, since cooler air is denser and heavier while hot air is lighter and will naturally move to the top. In essence you're going to be stagnating the heat in the case.

This was my initial reaction to the whole inverted layout thing since it's a completely new concept for me and I've always used air cooling.
I previously discussed this on another forum, and an experienced builder over there thought that a reasonably powerful top intake fan together with the GPU cooler fans will have enough power to keep pushing any "naturally" rising hot air back down, keeping it from rising up or "bouncing" all around. But I'm not sure if I believe him and if one exhaust in the lower corner could be enough to keep the heat from building up. It doesn't sound ideal at all. And could the airflow from the front be pushing out at least part of the top intake airflow before it reaches the GPU fans?

Out of curiosity, what fans do you have to work with? If it's those 3 fans listed, I'd remove the side panel fan and have fans at the front, then the rear and top. That way the front fans will draw in cooler ambient air and the top and rear will aid in exhaust.

If I end up buying the 802, I will be using the three Pure Wings fans that come with it and salvaging my 140mm Noctua from the old case to be placed as an additional exhaust or intake, depending on whether I will be trying out the normal or inverted layout. Although I'd rather have identical sets of fans in both ends, so I might buy another Noctua for the rear exhaust and possibly move the pre-installed Pure Wings from the back to the front as an intake. Or, in the standard layout, as a bottom intake under the GPU if it's possible.
The old Fractal stock fans are something I'm not planning to reuse.
The Pure Base 500DX comes with a default setup of one front intake, one rear exhaust and one top exhaust, and it performs way better in thermal testing. This is why one of the 802 reviewers decided to try the same setup on the 802 and the GPU temperatures went down significantly.
But would an extra intake hurt thermals in this configuration? The setup would then be 2x front intake, 1x rear exhaust, 1x top exhaust. It would allow for neutral pressure.

Physics was never a strong subject of mine. This whole planning stage has already been a wonderful recap of many of the basic concepts.

 

[hyperreal]

So, I got the case and succesfully moved my system into it, using the normal layout rather than inverted.
I'm happy to report that while the card runs significantly hotter at idle, in higher loads it actually seems to run cooler. And this is with the soundproofed panels. I did give the GPU assembly a whiff of air duster before installing it into the new case, so that could explain something.
Nevertheless, I'm happy with the case and the airflow is a definite improvement from my old, messy case. It's not as silent as I would have hoped and I blame the CPU cooler for that. I'll be replacing it with a more quiet model in the future.