New build suggestion: INSIDE CASE TOO HOT

[XHunTomo]

Hi everyone. I'm new to the LTT forum.

I'm Japanese pc builder, so please bear with my elementary English.

I am building my dream PC, and had tons of issues after finishing the build.

The main issue is the heat: its too hot my system is thermal throttling except for GPU. I've done weeks of research, testing, building, and even buying 2 new chassis ending up wasting tons of money, and at last I gave up.

This community is my last resort, and I really need your help.

 

Budget (including currency): Not much of a consideration at this point (JPY).

Country: Japan

Games, programs or workloads that it will be used for: Mainly heavy gaming. Also for minor encoding, few virtual computing.

 

Other details:

Listed below

Existing parts lists:

--MUST REMAIN THE SAME--

-GPU:MSI RTX 5090 Supreme liquid SOC 32GB

-CPU:Ryzen 9 9950x3d

-PSU: ROG STRIX 1200w platinum

-Mobo: MSI x870e GODLIKE

-------------------------------

-- I will change if necessary--

-AIO:ROG Ryujin II 360(3 years old)

-Memory: Corsair 32GB x2

-Chassis: Lian Li O11D EVO RGB White

-3 120mm noctua fans, other minor fans from random brands.

--------------------------------

 

Other Notes:

--LIMITATION--

-Small Japanese House, very limited place to put. Need to be under my desk.

-Chassis height limited to 68cm, realistically 63cm max. Width 33cm max. No problem with length.

-----------------

 

--Wants, if possible--

-Space for 2 HDD

-no top exhaust.

----------------------

 

--What I wasted--

-Fractal Design North XL (two radiators won't fit)

-Lian Li O11D EVO RGB White (bad airflow, too hot)

-Tons of money I spent on this stupid "dream" build.

-------------------

 

I recently won a lottery of "privilege to buy MSI liquid cooling RTX 5090".

I had to fit two 360mm radiator in one case for both RTX 5090 and Ryzen 9 9950x3d cooling, and end up reaching to Lian Li O11D EVO.

I ran the benchmark, and I was surprised by the cooling power of the RTX 5090, but at the same time the heat from the radiator is just too crazy.

The heat spread through the chassis, messing up every temperature of my build.

MOS temperature stuck on 61℃(141.8F?) after 1 hours of GPU stress testing, and it took around 30 minutes to cool down to 52℃.

Even during idle, my CPU temp is around 52~55℃, and opening browser will spike up to 70℃.

 

When I was using Fractal Design Torrent with same components except for RTX 5090, my idle CPU temp was around 46-50℃.

I borrowed ZOTAC 5090 amp extreme for testing, and even with the 80℃ monster, the temperature inside the case are way better than what I have currently.

 

My fan setup is listed below:

Top(CPU AIO cooler Intake

Bottom: Intake

Side(GPU AIO cooler): Exhaust (Push-Pull)

Front: Intake

Rear: Exhaust

 

I know top fan shouldn't be intake, but you probably don't know how small a Japanese house is.

I need to put the chassis under my desk, and if the top fan is set to exhaust, I would melt during gaming.

Thinking that, the Fractal Design Torrent was such an awesome chassis, perfect height, nice and cool airflow through back.

 

Any suggestion with the current parts list, no problem. If I need to change my chassis and CPU AIO cooler, no problem as well. Unless CPU, GPU, Mobo remains the same, I will change any parts as much as possible.

If the best option is to revert my build to Fractal Design Torrent and change CPU cooler to air cooling, that's also completely fine. Please suggest me with any possibility.

 

Thank you.

[ki8aras]

you're saying your build runs hot, however the only temperatures you mention are well within acceptable range

is your cpu actually thermal throttling? if so, is your aio's pump configured properly? its normal for cpu temps to randomly spike when using an AIO since the coldplate/pump that mounts on the cpu doesn't have a lot of thermal mass

[Needfuldoer]

Do you have adequate space for airflow around your PC? The best cooler won't do any good if the PC is trapped in a bubble of hot air.

 

12 minutes ago, XHunTomo said:

I need to put the chassis under my desk, and if the top fan is set to exhaust, I would melt during gaming.

You need at least as much air flow coming out of the case as you do going in. If you have six 120mm fans blowing "in", how much airflow do you have blowing "out"? If you only have one 120mm fan worth of space on the back of the PC open as the exhaust, then your cooling performance is compromised. PC fans don't blow very hard, so air pressure builds up inside your case and they move less air. A powerful exhaust fan might help, but 

 

Unfortunately, more PC fans and better heatsinks/AIOs won't make your space less warm, because your CPU and GPU are still generating the same amount of heat. No matter what, that heat energy will be exhausted into the room. You might as well flip the top fans around to exhaust.

 

Your temperatures aren't great, but they aren't horrible either.

[venomtail]

These are all quality parts, they have the thermal headroom to keep everything cool. Your listed temperatures are within norms at a glance. I think the issue might lie with the fan setup, maybe even a simple fan curve readjustment is needed.

 

Are all the fans sucking in air correctly through the bottom, sides and out the top, back?

 

Have you tried bumping up the fan speeds for different temps? Noctua fans can go to high RPM's whilst remaining quiet.

 

See if the fan setup is correct first, then see if simply tuning the fans for the temperature rise offsets it.

[PDifolco]

53 minutes ago, XHunTomo said:

Hi everyone. I'm new to the LTT forum.

I'm Japanese pc builder, so please bear with my elementary English.

I am building my dream PC, and had tons of issues after finishing the build.

The main issue is the heat: its too hot my system is thermal throttling except for GPU. I've done weeks of research, testing, building, and even buying 2 new chassis ending up wasting tons of money, and at last I gave up.

This community is my last resort, and I really need your help.

 

Budget (including currency): Not much of a consideration at this point (JPY).

Country: Japan

Games, programs or workloads that it will be used for: Mainly heavy gaming. Also for minor encoding, few virtual computing.

 

Other details:

Listed below

Existing parts lists:

--MUST REMAIN THE SAME--

-GPU:MSI RTX 5090 Supreme liquid SOC 32GB

-CPU:Ryzen 9 9950x3d

-PSU: ROG STRIX 1200w platinum

-Mobo: MSI x870e GODLIKE

-------------------------------

-- I will change if necessary--

-AIO:ROG Ryujin II 360(3 years old)

-Memory: Corsair 32GB x2

-Chassis: Lian Li O11D EVO RGB White

-3 120mm noctua fans, other minor fans from random brands.

--------------------------------

 

Other Notes:

--LIMITATION--

-Small Japanese House, very limited place to put. Need to be under my desk.

-Chassis height limited to 68cm, realistically 63cm max. Width 33cm max. No problem with length.

-----------------

 

--Wants, if possible--

-Space for 2 HDD

-no top exhaust.

----------------------

 

--What I wasted--

-Fractal Design North XL (two radiators won't fit)

-Lian Li O11D EVO RGB White (bad airflow, too hot)

-Tons of money I spent on this stupid "dream" build.

-------------------

 

I recently won a lottery of "privilege to buy MSI liquid cooling RTX 5090".

I had to fit two 360mm radiator in one case for both RTX 5090 and Ryzen 9 9950x3d cooling, and end up reaching to Lian Li O11D EVO.

I ran the benchmark, and I was surprised by the cooling power of the RTX 5090, but at the same time the heat from the radiator is just too crazy.

The heat spread through the chassis, messing up every temperature of my build.

MOS temperature stuck on 61℃(141.8F?) after 1 hours of GPU stress testing, and it took around 30 minutes to cool down to 52℃.

Even during idle, my CPU temp is around 52~55℃, and opening browser will spike up to 70℃.

 

When I was using Fractal Design Torrent with same components except for RTX 5090, my idle CPU temp was around 46-50℃.

I borrowed ZOTAC 5090 amp extreme for testing, and even with the 80℃ monster, the temperature inside the case are way better than what I have currently.

 

My fan setup is listed below:

Top(CPU AIO cooler Intake

Bottom: Intake

Side(GPU AIO cooler): Exhaust (Push-Pull)

Front: Intake

Rear: Exhaust

 

I know top fan shouldn't be intake, but you probably don't know how small a Japanese house is.

I need to put the chassis under my desk, and if the top fan is set to exhaust, I would melt during gaming.

Thinking that, the Fractal Design Torrent was such an awesome chassis, perfect height, nice and cool airflow through back.

 

Any suggestion with the current parts list, no problem. If I need to change my chassis and CPU AIO cooler, no problem as well. Unless CPU, GPU, Mobo remains the same, I will change any parts as much as possible.

If the best option is to revert my build to Fractal Design Torrent and change CPU cooler to air cooling, that's also completely fine. Please suggest me with any possibility.

 

Thank you.

If your PC is like mine under a desk, you'd better reverse fans for rear intake and front exhaust, so that hot air don't stay under the desk

To keep airflow balance use a 140mm fast fan at the rear , running relatively fast (I use a BQ SW4 Pro, it's still quiet at 1500rpm), and let the front fans at lower speed (say 1000rpm)

Your temps are fine, maybe 4-5C over a more "open" setup, but that's not an issue really, you can't expect a 800W PC to not heat the room anyway

[Amir F. Rad]

1 hour ago, XHunTomo said:

Hi everyone. I'm new to the LTT forum.

I'm Japanese pc builder, so please bear with my elementary English.

I am building my dream PC, and had tons of issues after finishing the build.

The main issue is the heat: its too hot my system is thermal throttling except for GPU. I've done weeks of research, testing, building, and even buying 2 new chassis ending up wasting tons of money, and at last I gave up.

This community is my last resort, and I really need your help.

 

Budget (including currency): Not much of a consideration at this point (JPY).

Country: Japan

Games, programs or workloads that it will be used for: Mainly heavy gaming. Also for minor encoding, few virtual computing.

 

Other details:

Listed below

Existing parts lists:

--MUST REMAIN THE SAME--

-GPU:MSI RTX 5090 Supreme liquid SOC 32GB

-CPU:Ryzen 9 9950x3d

-PSU: ROG STRIX 1200w platinum

-Mobo: MSI x870e GODLIKE

-------------------------------

-- I will change if necessary--

-AIO:ROG Ryujin II 360(3 years old)

-Memory: Corsair 32GB x2

-Chassis: Lian Li O11D EVO RGB White

-3 120mm noctua fans, other minor fans from random brands.

--------------------------------

 

Other Notes:

--LIMITATION--

-Small Japanese House, very limited place to put. Need to be under my desk.

-Chassis height limited to 68cm, realistically 63cm max. Width 33cm max. No problem with length.

-----------------

 

--Wants, if possible--

-Space for 2 HDD

-no top exhaust.

----------------------

 

--What I wasted--

-Fractal Design North XL (two radiators won't fit)

-Lian Li O11D EVO RGB White (bad airflow, too hot)

-Tons of money I spent on this stupid "dream" build.

-------------------

 

I recently won a lottery of "privilege to buy MSI liquid cooling RTX 5090".

I had to fit two 360mm radiator in one case for both RTX 5090 and Ryzen 9 9950x3d cooling, and end up reaching to Lian Li O11D EVO.

I ran the benchmark, and I was surprised by the cooling power of the RTX 5090, but at the same time the heat from the radiator is just too crazy.

The heat spread through the chassis, messing up every temperature of my build.

MOS temperature stuck on 61℃(141.8F?) after 1 hours of GPU stress testing, and it took around 30 minutes to cool down to 52℃.

Even during idle, my CPU temp is around 52~55℃, and opening browser will spike up to 70℃.

 

When I was using Fractal Design Torrent with same components except for RTX 5090, my idle CPU temp was around 46-50℃.

I borrowed ZOTAC 5090 amp extreme for testing, and even with the 80℃ monster, the temperature inside the case are way better than what I have currently.

 

My fan setup is listed below:

Top(CPU AIO cooler Intake

Bottom: Intake

Side(GPU AIO cooler): Exhaust (Push-Pull)

Front: Intake

Rear: Exhaust

 

I know top fan shouldn't be intake, but you probably don't know how small a Japanese house is.

I need to put the chassis under my desk, and if the top fan is set to exhaust, I would melt during gaming.

Thinking that, the Fractal Design Torrent was such an awesome chassis, perfect height, nice and cool airflow through back.

 

Any suggestion with the current parts list, no problem. If I need to change my chassis and CPU AIO cooler, no problem as well. Unless CPU, GPU, Mobo remains the same, I will change any parts as much as possible.

If the best option is to revert my build to Fractal Design Torrent and change CPU cooler to air cooling, that's also completely fine. Please suggest me with any possibility.

 

Thank you.

can you take your pc out of under the desk and in the middle of the room and run your stress tests again and see the temp diffrences please? just to eliminate the effect of the confined space, also if i was facing the same problem, i would put my most heat producing part`s radiator as an exhust, so the heat getting generated by that part wouldnt heat up inside the case, also if you are not sensitive to fan sound, run your fans faster or even buy some high power fans getting used in mining, they sound like jet engines and use really high power but have extrememly high cfm 

[XHunTomo]

On 4/22/2025 at 7:47 PM, ki8aras said:

you're saying your build runs hot, however the only temperatures you mention are well within acceptable range

is your cpu actually thermal throttling? if so, is your aio's pump configured properly? its normal for cpu temps to randomly spike when using an AIO since the coldplate/pump that mounts on the cpu doesn't have a lot of thermal mass

Hi ki8aras,

 

About thermal throttling, yes. I tried Cinebench R23.2 multicore single run, my score lowered from 41000 to 38500, no CPU OC.

Ambient temperature is usually 23~25 celcius, and if I turn on the air conditioner to 22 Celsius the score with max AIO fan speed increase to 40000 at best.

I'm very sensitive about this situation, because I build my friend's PC with North XL, MSI x870 tomahawk, Liquid Freezer III 360 , ZOTAC RTX 5090, and the rest similar configuration and similar ambient temp with no air conditioner, achieving 42300 stock setting. Maybe I'm being really paranoid, but I can't digest this score difference as a "margin of error"

 

As for AIO pump configuration, I did placed it properly for sure, but the pump is making coil wining-like sound. Lowering the pump speed to around 70% will remove the sound. Is my AIO broken? I didn't notice the noise back in the old configuration, because of closed top chassis? I don't know.

[XHunTomo]

On 4/22/2025 at 7:51 PM, Needfuldoer said:

Do you have adequate space for airflow around your PC? The best cooler won't do any good if the PC is trapped in a bubble of hot air.

 

You need at least as much air flow coming out of the case as you do going in. If you have six 120mm fans blowing "in", how much airflow do you have blowing "out"? If you only have one 120mm fan worth of space on the back of the PC open as the exhaust, then your cooling performance is compromised. PC fans don't blow very hard, so air pressure builds up inside your case and they move less air. A powerful exhaust fan might help, but 

 

Unfortunately, more PC fans and better heatsinks/AIOs won't make your space less warm, because your CPU and GPU are still generating the same amount of heat. No matter what, that heat energy will be exhausted into the room. You might as well flip the top fans around to exhaust.

 

Your temperatures aren't great, but they aren't horrible either.

 

Hi Needfuldoer,

 

I think this might be the biggest reason my PC is suffocating.

My current "out" is at the side and the back, and the very hot air from GPU radiator is releasing from side, sucking from top. I think this is the horrible loop.

It is very closed environment, and hot air might be circulating under my desk. I probably didn't have this issue because Torrent only had front bottom intake, back exhaust.

However, still not understanding why Cinebench R23 score is lowering. GPU is not running during the CPU testing, so not much hot air is circulating inside my PC.

 

I should try top exhaust once again, but also need to figure out how not to blow it out directly to my body... any suggestion is welcome.

Also, thanks for the relieving word about the temperatures. Maybe I'm just being paranoid.

[XHunTomo]

On 4/22/2025 at 8:27 PM, venomtail said:

These are all quality parts, they have the thermal headroom to keep everything cool. Your listed temperatures are within norms at a glance. I think the issue might lie with the fan setup, maybe even a simple fan curve readjustment is needed.

 

Are all the fans sucking in air correctly through the bottom, sides and out the top, back?

 

Have you tried bumping up the fan speeds for different temps? Noctua fans can go to high RPM's whilst remaining quiet.

 

See if the fan setup is correct first, then see if simply tuning the fans for the temperature rise offsets it.

Hi venomatail.

 

Fan setup is my worst nightmare currently.

I tried too many configuration, I don't know what is the ideal fan setup anymore.

 

Current setup is listed below:

Top(CPU AIO cooler) Intake

Bottom: Intake

Side(GPU AIO cooler): Exhaust (Push-Pull)

Front: Intake

Rear: Exhaust

 

Needfuldoer also pointed out that the top exhaust might be better too, so I think I should retry the fan setup.

As for fan curve, yes I did. Lower temp, lower RPM. My borderline of the temperature is 80 Celsius, so that's the ramp up point.

Some reason even with max CPU AIO fan, it still doesn't improve much of my Cinebench score. I'm wondering if my AIO is simply broken, or there is issue with my drivers or BIOS setting.

[XHunTomo]

On 4/22/2025 at 8:37 PM, PDifolco said:

If your PC is like mine under a desk, you'd better reverse fans for rear intake and front exhaust, so that hot air don't stay under the desk

To keep airflow balance use a 140mm fast fan at the rear , running relatively fast (I use a BQ SW4 Pro, it's still quiet at 1500rpm), and let the front fans at lower speed (say 1000rpm)

Your temps are fine, maybe 4-5C over a more "open" setup, but that's not an issue really, you can't expect a 800W PC to not heat the room anyway

Hi PDifolco,

 

Thanks for the suggestion.

Rear/back intake, front exhaust is totally a blind spot for me. I should try that.

Unfortunately, this Lian Li case can only place 120mm fan for rear, so I will look for BQ SW4 Pro. Honestly I didn't know there was an expensive fan than Noctua lol.

Also, again, thanks for the relieving word about the temperatures. Now I have a feeling I'm really just being paranoid about the situations.

[XHunTomo]

On 4/22/2025 at 9:00 PM, Amir F. Rad said:

can you take your pc out of under the desk and in the middle of the room and run your stress tests again and see the temp diffrences please? just to eliminate the effect of the confined space, also if i was facing the same problem, i would put my most heat producing part`s radiator as an exhust, so the heat getting generated by that part wouldnt heat up inside the case, also if you are not sensitive to fan sound, run your fans faster or even buy some high power fans getting used in mining, they sound like jet engines and use really high power but have extrememly high cfm 

Hi Amir F.Rad,

 

I tried it with much more open space, and actually the case hotness is much better than before.

I think we have same conclusion at this point. Since the radiator for GPU is the most heat conductor, I set it as exhaust, but the air release is circulated back in from top intake fans. 

 

Since my PC is close to my body, maybe using extreme fan is not my option. Still, I will try to get a high performance fans like Noctua or BQ SW4 Pro for better airflow solution. Thanks for the suggestion.

[venomtail]

1 hour ago, XHunTomo said:

Fan setup is my worst nightmare currently.

I tried too many configuration, I don't know what is the ideal fan setup anymore.

 

Current setup is listed below:

Top(CPU AIO cooler) Intake

That's one of the problems here. Top exhaust should always be an exhaust. As physics tell us, hot air rises naturally. If you have fans blowing out on top, great, hot air gets to rise even more and leaves the case, however if hot air wants to rise and top fans keep pushing it back down again, it's a mess and it starts harming your airflow.

 

 

1 hour ago, XHunTomo said:

My borderline of the temperature is 80 Celsius, so that's the ramp up point.

Also fan curve should be smooth. If you have a flat line that picks up only at 80C then it's not an optimal fan curve. 

 

[Amir F. Rad]

12 hours ago, XHunTomo said:

Hi Amir F.Rad,

 

I tried it with much more open space, and actually the case hotness is much better than before.

I think we have same conclusion at this point. Since the radiator for GPU is the most heat conductor, I set it as exhaust, but the air release is circulated back in from top intake fans. 

 

Since my PC is close to my body, maybe using extreme fan is not my option. Still, I will try to get a high performance fans like Noctua or BQ SW4 Pro for better airflow solution. Thanks for the suggestion.

put a piece of card board over the case to eliminate the hot air goes back inside the case again for an examination, if it improves your temps then you can think of something to phisically seperate top inlet and front exhust, also dont cover the top fans when you trying to put the cardboard, it is just a test to find the reason, before doing anything else or buy anything more, first identify the problem, then try a fix, also i had similar problems a while back my cpu was thermal throthling all the time i didnt know why while my cpu cooler was noctua nh d14 which is a very good cpu cooler even now, at last i identified the problem and it was thermal paste, i live in iran and couldnt find any proper thermal paste, at last when i used a 13w/mk thermal paste everything got solved finally and when i used mining fans, my temps droped by 10degree

[XHunTomo]

On 4/24/2025 at 4:37 PM, venomtail said:

That's one of the problems here. Top exhaust should always be an exhaust. As physics tell us, hot air rises naturally. If you have fans blowing out on top, great, hot air gets to rise even more and leaves the case, however if hot air wants to rise and top fans keep pushing it back down again, it's a mess and it starts harming your airflow.

 

 

Also fan curve should be smooth. If you have a flat line that picks up only at 80C then it's not an optimal fan curve. 

 

 

Thank you for the video. I was looking for clear explanation of the airflow and the video was really ideal.

The one from 6:39 looks similar to what I have, and top exhaust is simply a MUST for such builds.

 

And yes, my fan curve was very crap. I changed to lot more smooth fan curve like yours, the in case temp was lot better than before.

I focused too much on silence during low workload.

 

Thanks for lots of idea. I think I can move on to the proper setup now.

[XHunTomo]

On 4/25/2025 at 4:21 AM, Amir F. Rad said:

put a piece of card board over the case to eliminate the hot air goes back inside the case again for an examination, if it improves your temps then you can think of something to phisically seperate top inlet and front exhust, also dont cover the top fans when you trying to put the cardboard, it is just a test to find the reason, before doing anything else or buy anything more, first identify the problem, then try a fix, also i had similar problems a while back my cpu was thermal throthling all the time i didnt know why while my cpu cooler was noctua nh d14 which is a very good cpu cooler even now, at last i identified the problem and it was thermal paste, i live in iran and couldnt find any proper thermal paste, at last when i used a 13w/mk thermal paste everything got solved finally and when i used mining fans, my temps droped by 10degree

You made a really good point.

I was really paranoid when making this pc, and just randomly bought some stuff to fix the problem. Bad move.

 

Changing thermal paste might be another solution. Let me test it and see how things change.

Ill try the cardboard method as well, and see the difference.

Thanks for the idea.

[XHunTomo]

Hi everyone.

So, after another testing, I changed my front fan from three 120mm fans to two 140mm Noctua fans, top fans to exhaust, change CPU paste to the one with around 13w/mk, put a caster under my PC to move out ambient temperature during high load.

With all of these testing, my case temperature decreased drastically, for both CPU and GPU.

My Cinebench score become around 40500, and for 3DMark Steel Nomad DX12 bench I achieved "Cool under pressure" and "Excellent" achievement at the same time. I wasn't even bothering about GPU performance boost, but it simply did as a "by-product" and I'm totally happy with it.

 

I really want to give you all the best answer mark, but since its only for one reply, I'm giving out Amir F. Rad for basically "calmed me down", and point out about the importance of good fan and the effect of confined spaces.

 

Thank you all for your helpful responses!