Question Best way to ensure maximum cooling in my build?

cogsman

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Dec 27, 2020
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So my rig is a Ryzen 9 5900X on an ASUS mITX B550-i Gaming MB, cooled by a Dark Rock Pro 4, in a Thermaltake V21 chassis. GPU is a 3-fan EVGA RTX 3070 XC3 Ultra. In addition to the front 200mm Thermaltake Pure case fan running at 800RPM with a 130 CFM airflow, I also have a Pure Wings 2 140mm fan at the rear exhausting out (in line with the DRP4) and another PW2 140mm at the rear right exhausting out (to the right of the DRP4).

As you can imagine, things are very tight in that back corner! The rear fan frame is almost touching the DRP4 (the right side fan is about 1cm away). Basically the cooler is blowing in a push/pull config, theoretically exhausting into the rear 140mm fan, with the rear right fan helping to pull some more air out.

With the fan speeds set to Full Speed using the ASUS app, I am consistently seeing 90C max with 89C average on Cinebench R23 multi core tests. I have PBO on, but given Ryzen Master and HWInfo's reporting, I doubt I have any headroom for further overclocking under the current config, though I may be wrong.

In a previous thread, someone suggested this is completely in line with expectations of an air cooler and 5900X under load.

I wonder... does the ITX footprint in this V21 case, and with the rear exhaust fans and cooler packed so close together potentially promote higher temps, i.e the airflow profile is not efficient?

I have been toying with a few ideas:
  1. Add 1 Pure Wings 2 140mm (62 CFM) to the right side of the chassis to pull more air out, though this fan would sit closer to the front end of the case instead of the rear and would thus not be near the cooler, OR
  2. Replace the front 200mm fan with 2 vertically mounted Pure Wings 2 140mm fans (62 CFM each) connected to the case fan header (for a total of 4 on that header) to get more air blowing into the case (though not sure the CFM math works there), OR
  3. Replace the DRP4 with a Noctua NH-12A to provide more clearance and theoretically better airflow (but maybe not be able to cool as efficiently as the DRP4), OR
  4. Replace the DRP4 with a Noctua NH-12A AND add 1 Pure Wings 2 140mm to the right side of the chassis as I mentioned in #1 above, OR
  5. Remove the rear 140mm fan to provide more clearance (and let the DRP4 just blow through the back unobstructed), but then that would remove one fan that is pulling air out, assuming that fan is actually helping.
I was also thinking of using an AIO like be quiet's model with the external pump, but not sure I want to go that route. Price-wise Air or AIO options described here are all pretty much the same in Canada, about $110-$130 CAD.

Does anyone think that any of these strategies would result in markedly lower thermals (say 8-10C?) or is it just best to leave it as is?

Any ideas/feedback are welcome. My goal: provide maximum cooling performance for the dollars spent.
 

iPeekYou

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Jul 7, 2014
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So my rig is a Ryzen 9 5900X on an ASUS mITX B550-i Gaming MB, cooled by a Dark Rock Pro 4, in a Thermaltake V21 chassis. GPU is a 3-fan EVGA RTX 3070 XC3 Ultra. In addition to the front 200mm Thermaltake Pure case fan running at 800RPM with a 130 CFM airflow, I also have a Pure Wings 2 140mm fan at the rear exhausting out (in line with the DRP4) and another PW2 140mm at the rear right exhausting out (to the right of the DRP4).

As you can imagine, things are very tight in that back corner! The rear fan frame is almost touching the DRP4 (the right side fan is about 1cm away). Basically the cooler is blowing in a push/pull config, theoretically exhausting into the rear 140mm fan, with the rear right fan helping to pull some more air out.

With the fan speeds set to Full Speed using the ASUS app, I am consistently seeing 90C max with 89C average on Cinebench R23 multi core tests. I have PBO on, but given Ryzen Master and HWInfo's reporting, I doubt I have any headroom for further overclocking under the current config, though I may be wrong.

In a previous thread, someone suggested this is completely in line with expectations of an air cooler and 5900X under load.

I wonder... does the ITX footprint in this V21 case, and with the rear exhaust fans and cooler packed so close together potentially promote higher temps, i.e the airflow profile is not efficient?

I have been toying with a few ideas:
  1. Add 1 Pure Wings 2 140mm (62 CFM) to the right side of the chassis to pull more air out, though this fan would sit closer to the front end of the case instead of the rear and would thus not be near the cooler, OR
  2. Replace the front 200mm fan with 2 vertically mounted Pure Wings 2 140mm fans (62 CFM each) connected to the case fan header (for a total of 4 on that header) to get more air blowing into the case (though not sure the CFM math works there), OR
  3. Replace the DRP4 with a Noctua NH-12A to provide more clearance and theoretically better airflow (but maybe not be able to cool as efficiently as the DRP4), OR
  4. Replace the DRP4 with a Noctua NH-12A AND add 1 Pure Wings 2 140mm to the right side of the chassis as I mentioned in #1 above, OR
  5. Remove the rear 140mm fan to provide more clearance (and let the DRP4 just blow through the back unobstructed), but then that would remove one fan that is pulling air out, assuming that fan is actually helping.
I was also thinking of using an AIO like be quiet's model with the external pump, but not sure I want to go that route. Price-wise Air or AIO options described here are all pretty much the same in Canada, about $110-$130 CAD.

Does anyone think that any of these strategies would result in markedly lower thermals (say 8-10C?) or is it just best to leave it as is?

Any ideas/feedback are welcome. My goal: provide maximum cooling performance for the dollars spent.

8-10C is quite a task to achieve. Not impossible, but usually I see improvements at that range for horribly ventilated systems (think old mATX or ATX cases from the era where only a single 80mm exhaust fan is guaranteed --front ventilation a bonus). Or in modern cases where the front panel is a solid construction with little to no vents to draw air from.

Disclaimer: I haven't had much experience with form factors smaller than mATX --only have one tiny case in my collection that I retired already to a much bigger case once space allows.

From what I understand, your setup is quite near the edge of what's possible with that case --short of doing a crazy custom loop inside. To be fair, 5900Xs run hot, there's no way around it. Even Zen 2 chips were warm considering what we're used to in the last Ivy Bridge era revolution.

According to my experiments with airflow (on a small mATX case and a small ATX one, both with unobstructed airflow up front save for dust filters), there's really little to gain from front intake fans when you hit certain airflow. That airflow threshold is quite low to boot for intakes, exhaust fans benefit better from the upgrade in airflow capacity. Some say it's due to the less restrictions on exhaust fans than the obligatory dust filters/similar material for intake, but I stick to the common sense where exhausting a room (or a system) is more efficient for heat removal rather than intake.

Aside from not needing much airflow, there's also the importance of airflow. You'd need a good flow of air and not just brute force CFM and/or static pressure. This is especially true if we're dealing with decent fans --to say nothing of crappy, 1 dollar LED fans. You've got a decent flow setup front to back already, there's really little to go from there. If you want to guarantee good cooling, airflow is your best friend. Brute force or not, it's a guarantee. As close as it gets considering the erratic airflow inside a PC case.

All I can think of is either going custom loop (difficult in a small case) or go large chassis. More space really helps in cooling things down --I see a consistent 3-4C drop in maximum CPU temps under OCCT small going from mATX to just a small ATX (as in mid towers with barely enough space for ATX motherboards). Think of it like standing near a bonfire. It's easier to cool down by just stepping back a few steps from the fire rather than rely on wind breeze. You'd need a real strong wind to cool down as opposed to just spacing things apart.
 
Jul 19, 2021
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You need to plan your cooling to maintain the required pressure inside the case, and minimise the power dissipation inside it.
so you need to look at the specs of the fans their flow rates and pressure rating.
Is the case sealed except for where fans are fitted?
Are there any obstructions (inside or outside) to hinder air flow? Is the intake drawing in warm air from the exhaust?

Can you water cool and fit an external radiator?

http://www.skillbank.co.uk/cooling.html
 

cogsman

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Dec 27, 2020
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You need to plan your cooling to maintain the required pressure inside the case, and minimise the power dissipation inside it.
so you need to look at the specs of the fans their flow rates and pressure rating.
Is the case sealed except for where fans are fitted?
Are there any obstructions (inside or outside) to hinder air flow? Is the intake drawing in warm air from the exhaust?

Can you water cool and fit an external radiator?

http://www.skillbank.co.uk/cooling.html


The case is drilled holes on all sides except 1 panel which is a plastic window.

CFM on my two be quiet fans is 61.2, and air pressure is 0.76

CFM on front fan is 130, and air pressure in 0.996

CFM for the Dark Rock Pro 4: it uses one 120mm Silent Wings 3 fan, rated at 85.8 CFM and 1.76 air pressure, and it also uses a 135mm Silent Wings fan but I cannot find the specs on that one. I assume it must be essentially the same as the other fan or it would be unbalanced airflow.

Yes. I have room for up to a 280mm radiator inside the case; I would not mount one outside.
 

cogsman

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Dec 27, 2020
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This is the visual. 3 fans on the video card. PSU at the bottom. The panels were removed for this pic but top is a window panel with no ventilation and all other sides are drilled metal. Any suggestions?

 

Phaaze88

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This is the visual. 3 fans on the video card. PSU at the bottom. The panels were removed for this pic but top is a window panel with no ventilation and all other sides are drilled metal. Any suggestions?
Thermaltake V21
If I remember correctly, the 3 outer panels can be swapped around on that chassis, right?
Do away with the fan on the right side - it's T-boning what should be a straight front to back airflow setup.
Put the windowed panel on the side where the disruptive fan was. Now you have ventilation over the areas that matter most.

The gpu draws air from the side its fans are facing. It dumps it's waste heat in the direction the fin stacks are aimed, which is the sides:
-on the side you can't see, it's absorbed by the motherboard, as well as recirculating inside the chassis.
-on the side you can see, it can be readily exhausted out the chassis if you moved the windowed panel as I mentioned earlier.
The gpu is by far the biggest heat producer, so having the windowed panel at the top isn't doing it any favors for exhaust.

Also, consider removing those 3 PCIe slot guards, except if you have curious kids or pets that like to stick their hands/paws into open gaps.
They're not filtered anyway, and removing them will allow the gpu some more access to air from the rear as a bonus.
 

cogsman

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Dec 27, 2020
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Thanks Phaaze88. I followed your suggestions and I appreciate the logic behind them. This is the result. Temps have gone up 1-2 degrees C. Also I never noticed the Power Reporting Deviation warning before. Does anyone know what that's about? I can't make heads or tails of the online explanations. Is it time to go with a liquid cooler? FYI, final Cinebench score was 20997.

screenshot program windows
 
Last edited:

Phaaze88

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Power Reporting Deviation
If I recall correctly, it's just another way of saying:
The stock bios was tweaked by the board vendor for more performance by ~THIS MUCH.
It wasn't very accurate unless the user monitors it while running a heavy load, such as Cinebench R23.

Liquid coolers aren't an absolute fix. They've got their share of upsides as well as downsides.

@drea.drechsler
What do you think of the cooling situation here?