PC Thermals: Unobstructed v Partially Obstructed v Fully Obstructed Front Case

[Ralfi]

Hey people. I'm back again with more thermal testing (following on from here & here), this time seeing the difference between a case with its naturally unobstructed mesh front, versus a partially obstructed front (leaving only the side slits as air intakes), versus a completely obstructed front with all 3 front fans blocked.

 

So, here's how i've set up each scenario...Two layers of thick packing foam to block any air - the light shining through them makes them look a little hollow, however no air was getting though one of them, but I added two to remove all doubt. Used a hefty metal bracket to push the two larger pieces of foam toward the case to make sure the sides weren't letting air sneak in...

 

I have 4 intake fans & 2 exhausts cooling the below system:

• CPU
  AMD Ryzen 5 5600X
• Motherboard
  Gigabyte B550 AORUS PRO AX
• RAM
  Crucial Ballistix 16 GB (2 x 8 GB) DDR4-3600 CL16
• GPU
  PowerColor Radeon RX 6700 XT
• Case
  Corsair 4000D Airflow (White)
• Storage
  1: Kingston A2000 1 TB M.2-2280 NVME SSD
  2: Kingston KC2500 2TB M.2-2280 NVME SSD
  3. Western Digital Blue 500 GB 2.5" SSD
• PSU
  Corsair RMx850
• Cooling
  CPU Cooler: Deepcool GAMMAXX 400 V2 Heatsink + Arctic BioniX P120 A-RGB Fan
  Case Fan: Arctic BioniX P120 A-RGB x 5 + Cosair 4000D case fan x 1
  
  

I've collected CPU/GPU/GPU Hot Spot temps as well as all the sensor temps across the Motherboard, & calculated their Above-Ambient (A-A) results in each of the 3 case scenarios. I then worked out the A-A averages across the Motherboard & also the A-A averages across the total system (CPU/GPU/GPU Hot Spot/Motherboard).

 

Here are CPU/GPU/GPU Hot Spot temps:

 

From Unobstructed to Partially Obstructed, temps increased between ~1-2°.

From Partially Obstructed to Fully Obstructed, temps increased between ~1-3°.

From Unobstructed to Fully Obstructed, temps increased between ~Over 2°-Over 5°.

 

Here are the Motherboard sensor temps:

 

From Unobstructed to Partially Obstructed, temps increased between 2-Over 4°.

From Partially Obstructed to Fully Obstructed, temps increased between 0-7°.

From Unobstructed to Fully Obstructed, temps increased between 0-Over 9°.

 

Here are the averages across the Motherboard's sensors & also across the whole system:

 

When averaged out, I saw over 4° rise from Unobstructed to Fully Obstructed across the board & across the whole system.

 

It appears that by having a solid front panel, you're going to place your CPU fan under much more strain - I saw a 400RPM boost when the front was fully blocked. Luckily, my CPU fan's efficient when it comes to noise & I didn't notice any dB increase, but if you're using a CPU cooler that's not as proficient at higher RPM, you may hear it & perhaps even kill it sooner.

 

So in summary, as expected, solid front panel-designed cases hinder your cooling efficiency across your whole system. Not only do you need to think of your CPU/GPU, but you need your whole rig to breath. Invest in a case focussed on airflow & a fan orientation that compliments it.

 

P.S. In case you're curious, here are the full temps used in this test (via an Excel spreadsheet I created that auto-calculates all the above-ambient temps from the actual temps gathered)...

 

I also did the same above testing with 3 intake fans after disabling the Top-Front fan. I may have been incorrect in my thinking that having a Top-Front fan would help greatly as I didn't see a big increase in temps, in fact, average temps lowered on more occasions with 3 intake...

 

[NorKris]

very nice!

also this is a very good look for ur pc man! 

 

[thrasher_565]

4 hours ago, Ralfi said:

Hey people. I'm back again with more thermal testing (following on from here & here), this time seeing the difference between a case with its naturally unobstructed mesh front, versus a partially obstructed front (leaving only the side slits as air intakes), versus a completely obstructed front with all 3 front fans blocked.

 

So, here's how i've set up each scenario...Two layers of thick packing foam to block any air - the light shining through them makes them look a little hollow, however no air was getting though one of them, but I added two to remove all doubt. Used a hefty metal bracket to push the two larger pieces of foam toward the case to make sure the sides weren't letting air sneak in...

 

I have 4 intake fans & 2 exhausts cooling the below system:

• CPU
  AMD Ryzen 5 5600X
• Motherboard
  Gigabyte B550 AORUS PRO AX
• RAM
  Crucial Ballistix 16 GB (2 x 8 GB) DDR4-3600 CL16
• GPU
  PowerColor Radeon RX 6700 XT
• Case
  Corsair 4000D Airflow (White)
• Storage
  1: Kingston A2000 1 TB M.2-2280 NVME SSD
  2: Kingston KC2500 2TB M.2-2280 NVME SSD
  3. Western Digital Blue 500 GB 2.5" SSD
• PSU
  Corsair RMx850
• Cooling
  CPU Cooler: Deepcool GAMMAXX 400 V2 Heatsink + Arctic BioniX P120 A-RGB Fan
  Case Fan: Arctic BioniX P120 A-RGB x 5 + Cosair 4000D case fan x 1

I've collected CPU/GPU/GPU Hot Spot temps as well as all the sensor temps across the Motherboard, & calculated their Above-Ambient (A-A) results in each of the 3 case scenarios. I then worked out the A-A averages across the Motherboard & also the A-A averages across the total system (CPU/GPU/GPU Hot Spot/Motherboard).

 

Here are CPU/GPU/GPU Hot Spot temps:

 

From Unobstructed to Partially Obstructed, temps increased between ~1-2°.

From Partially Obstructed to Fully Obstructed, temps increased between ~1-3°.

From Unobstructed to Fully Obstructed, temps increased between ~Over 2°-Over 5°.

 

Here are the Motherboard sensor temps:

 

From Unobstructed to Partially Obstructed, temps increased between 2-Over 4°.

From Partially Obstructed to Fully Obstructed, temps increased between 0-7°.

From Unobstructed to Fully Obstructed, temps increased between 0-Over 9°.

 

Here are the averages across the Motherboard's sensors & also across the whole system:

 

When averaged out, I saw over 4° rise from Unobstructed to Fully Obstructed across the board & across the whole system.

 

It appears that by having a solid front panel, you're going to place your CPU fan under much more strain - I saw a 400RPM boost when the front was fully blocked. Luckily, my CPU fan's efficient when it comes to noise & I didn't notice any dB increase, but if you're using a CPU cooler that's not as proficient at higher RPM, you may hear it & perhaps even kill it sooner.

 

So in summary, as expected, solid front panel-designed cases hinder your cooling efficiency across your whole system. Not only do you need to think of your CPU/GPU, but you need your whole rig to breath. Invest in a case focussed on airflow & a fan orientation that compliments it.

 

P.S. In case you're curious, here are the full temps used in this test (via an Excel spreadsheet I created that auto-calculates all the above-ambient temps from the actual temps gathered)...

 

I also did the same above testing with 3 intake fans after disabling the Top-Front fan. I may have been incorrect in my thinking that having a Top-Front fan would help greatly as I didn't see a big increase in temps, in fact, average temps lowered on more occasions with 3 intake...

 

but you still have a top fan... unless you blocked that off too?

[Ralfi]

12 hours ago, thrasher_565 said:

but you still have a top fan... unless you blocked that off too?

No I used that, as it was part of my original setup. & found it made little difference as after I disabled it, average temps above ambient didn’t really change. In fact, they were better more often than not..

 

Edit...

Actually, looking over my prior testing comparing 4 intakes/2 exhausts v 3 intakes/2 exhausts, it appears the former had better temps after 60 minutes, but mainly for the GPU Hot Spot.

[thrasher_565]

7 hours ago, Ralfi said:

No I used that, as it was part of my original setup. & found it made little difference as after I disabled it, average temps above ambient didn’t really change. In fact, they were better more often than not..

 

Edit...

Actually, looking over my prior testing comparing 4 intakes/2 exhausts v 3 intakes/2 exhausts, it appears the former had better temps after 60 minutes, but mainly for the GPU Hot Spot.

gpus benefit form air because some exhaust out the side at the window will go up and some will go down and get sucked back in to the gpu so having air flow helps push it to the back so the back fan can suck it up. cant really do anything about the back exhaust of the gpu at the mb i wounder what blocking it off will do??? some mb with the northbrige fan had the gpu exhaust right in to it destroying there ocing...

 

bottom intake would be better at this but having something is better then nothing. Major Hardware did a 3d printed shroud that intakes front the pci slots and improves gpu cooling when bottom intake is not there or cases with crap fronts

 

ideally you would want you gpu mounted els ware ware it can intake and exhaust  the hot air out like thow wc case back in the day... i will do a mod in my antec lanboy some day that will do just that intake from the front and out the sides.

 

alot of gpus have crap plastic on the sides the reduce the exhaust speed...

Edited May 22 by thrasher_565

[Ralfi]

39 minutes ago, thrasher_565 said:

Major Hardware did a 3d printed shroud that intakes front the pci slots and improves gpu cooling when bottom intake is not there or cases with crap fronts

Yeah, I plan on doing something similar because it seemed to work a treat!

 

40 minutes ago, thrasher_565 said:

ideally you would want you gpu mounted els ware ware it can intake and exhaust  the hot air out like thow wc case back in the day... i will do a mod in my antec lanboy some day that will do just that intake from the front and out the sides.

Exhaust out the side panel (fan vent) in my old case worked very well. I guess case manufacturers don't put holes in their glass side panels is due to (a) Cost & (b) The air coming out the case may be distracting for the user if they sit next to it? 

 

They should do it though, as the main GPU exhaust is facing that side (at least it is on my 6000 series GPU).

43 minutes ago, thrasher_565 said:

i will do a mod in my antec lanboy some day that will do just that intake from the front and out the sides.

Interested in how that turns out.

[thrasher_565]

18 hours ago, Ralfi said:

Yeah, I plan on doing something similar because it seemed to work a treat!

 

Exhaust out the side panel (fan vent) in my old case worked very well. I guess case manufacturers don't put holes in their glass side panels is due to (a) Cost & (b) The air coming out the case may be distracting for the user if they sit next to it? 

 

They should do it though, as the main GPU exhaust is facing that side (at least it is on my 6000 series GPU).

Interested in how that turns out.

well it would but ya come down to cost. that's why case are flat in the back and use a pci slot cover as it much easier to manufatur. same reason they dont manly add wire grills to fans because of the laber and lazier cutting is a thing now. back then it was all stamped.

 

the side mesh / fans were mostly for sli as gpu only had like 1/8 between them so they ran HOT and loud. and most people got the blower gpus as they were cheaper.

4 years was considered good for a gpu at that time... but we didn't really no much about cooling and case just Brut forced it add as many fans as posable kinda deal.

 

sff case do have mesh on the side.

 

case like the lian li lancool 2 is an example of a case that has a basement but also can have bottom mount fans. but i guess if gpus are getting hotter then most likely the case market will change might see some nice wc cases again...