AIO are worse for airflow

[Kazualty]

I don't know why this seems so controversial but people seem to think when an AIO is set to exhaust that airflow is unaffected within the case. The rad itself is restrictive which can be overcome with better fans or more noise. However using a big air cooler with the same good fans in the case you can get better airflow to other components with less noise. 

 

I've also found through testing at least on a couple cases if you set top front fan to intake, remove top back fan and block off hole with something (black cardboard is usually easiest), front intake, rear exhaust, you end up with more fresh air to components and all air forced out back openings creating a front to back flow over all components. This lowered temps on my CPU, gpu and VRM. This setup is not really possible with an AIO unless it's used as intake which isn't great but if you already do that it could improve gpu temps and other components.

 

Anyways my point is radiators do block some airflow and it is generally quieter to use air cooling if you aren't pushing huge overclocks and comparing clock to clock. Instead comparing fan+pump noise and how much air is moving you can achieve better results with air if seeking silence. The only thing AIO are better for is CPU temps. Also better for small cases that don't fit decent sized coolers. This also wouldn't apply to stock cooling or anything small I'm comparing a good air cooler vs AIO. 

 

Has anyone made a video testing this? I don't have an AIO to show different airflow rates or compare component temps. Would like to see a comparison. I don't see why this isn't all obvious but I've been getting a lot of pushback when suggesting big air over AIO on some subreddits (mostly to people who don't plan on overclocking). 

[LIGISTX]

48 minutes ago, Kazualty said:

I don't know why this seems so controversial but people seem to think when an AIO is set to exhaust that airflow is unaffected within the case. The rad itself is restrictive which can be overcome with better fans or more noise. However using a big air cooler with the same good fans in the case you can get better airflow to other components with less noise. 

 

I've also found through testing at least on a couple cases if you set top front fan to intake, remove top back fan and block off hole with something (black cardboard is usually easiest), front intake, rear exhaust, you end up with more fresh air to components and all air forced out back openings creating a front to back flow over all components. This lowered temps on my CPU, gpu and VRM. This setup is not really possible with an AIO unless it's used as intake which isn't great but if you already do that it could improve gpu temps and other components.

 

Anyways my point is radiators do block some airflow and it is generally quieter to use air cooling if you aren't pushing huge overclocks and comparing clock to clock. Instead comparing fan+pump noise and how much air is moving you can achieve better results with air if seeking silence. The only thing AIO are better for is CPU temps. Also better for small cases that don't fit decent sized coolers. This also wouldn't apply to stock cooling or anything small I'm comparing a good air cooler vs AIO. 

 

Has anyone made a video testing this? I don't have an AIO to show different airflow rates or compare component temps. Would like to see a comparison. I don't see why this isn't all obvious but I've been getting a lot of pushback when suggesting big air over AIO on some subreddits (mostly to people who don't plan on overclocking). 

They do impede airflow, but there are lots of factors that go into cooling a PC case and the things in it efficiently.

 

1 immediate advantage is a radiator as an exhaust will remove almost all of the heat from that component from the case outright; very little heat is dumped into the case and thus other components are kept cooler. Does this mitigate the drop in airflow, possibly? Possibly not?

 

AIO’s have gained popularity because of “cool factor”, not really because of actual cooling ability. As you stated, a big air cooler is just as, if not more affective. The real way to get a quiet PC with good thermals is a custom loop… and this is mostly due to GPU cooling. Stock GPU fans are just not effective at both cooling and staying quiet. Some of the larger 3 slot heatsinks do a pretty good job, but my system is a good example of a system built around silence - all fans run 900 rpm or less in game load, CPU is typically low 60’s and GPU is high 40’s to low 50’s. I could drop fan RPM even further, but at under 900 rpm, I really can’t hear them anyways with any amount of game noises… water cooling does have a purpose and a place, but to get the true benefits of it, you need a good amount of rad space and have both CPU and GPU waterblocked. That said, my loop all in cost over 700 bucks, hell, fittings alone were over 150. So it’s not exactly bang for buck, but it’s fun (if your an enthusiast and enjoy it) and effective. 

[Kazualty]

16 minutes ago, LIGISTX said:

They do impede airflow, but there are lots of factors that go into cooling a PC case and the things in it efficiently.

 

1 immediate advantage is a radiator as an exhaust will remove almost all of the heat from that component from the case outright; very little heat is dumped into the case and thus other components are kept cooler. Does this mitigate the drop in airflow, possibly? Possibly not?

 

AIO’s have gained popularity because of “cool factor”, not really because of actual cooling ability. As you stated, a big air cooler is just as, if not more affective. The real way to get a quiet PC with good thermals is a custom loop… and this is mostly due to GPU cooling. Stock GPU fans are just not effective at both cooling and staying quiet. Some of the larger 3 slot heatsinks do a pretty good job, but my system is a good example of a system built around silence - all fans run 900 rpm or less in game load, CPU is typically low 60’s and GPU is high 40’s to low 50’s. I could drop fan RPM even further, but at under 900 rpm, I really can’t hear them anyways with any amount of game noises… water cooling does have a purpose and a place, but to get the true benefits of it, you need a good amount of rad space and have both CPU and GPU waterblocked. That said, my loop all in cost over 700 bucks, hell, fittings alone were over 150. So it’s not exactly bang for buck, but it’s fun (if your an enthusiast and enjoy it) and effective. 

I agree as far as water cooling having it's place especially when going custom. But the advantage you mentioned can be had at a lower noise with case fans in place of the rad. More fans total but no pump and no need for higher static pressure to overcome rad. Can either use quieter fans or go lower rpm with same fans. 

 

As far as I've seen assuming you don't want max overclock potential air wins in every way except CPU temps. Aio are a metal mesh wall blocking an entire panel. It's not drastic and I'm sure for most the extra noise isn't a problem but it's also way more expensive for a reasonable AIO and the longevity of pumps is not great. 

 

I'd just like to see this AIO fad come to an end. To me it just looks like people don't know what they are doing. If people were more educated about this I would hope that AIO would see less use. Especially considering most people would see bigger benefits from lower GPU temps that are improved with good airflow.

[Jeppes]

32 minutes ago, Kazualty said:

I agree as far as water cooling having it's place especially when going custom. But the advantage you mentioned can be had at a lower noise with case fans in place of the rad. More fans total but no pump and no need for higher static pressure to overcome rad. Can either use quieter fans or go lower rpm with same fans. 

 

As far as I've seen assuming you don't want max overclock potential air wins in every way except CPU temps. Aio are a metal mesh wall blocking an entire panel. It's not drastic and I'm sure for most the extra noise isn't a problem but it's also way more expensive for a reasonable AIO and the longevity of pumps is not great. 

 

I'd just like to see this AIO fad come to an end. To me it just looks like people don't know what they are doing. If people were more educated about this I would hope that AIO would see less use. Especially considering most people would see bigger benefits from lower GPU temps that are improved with good airflow.

Aio:s are great for gpu:s. Its nice to have that +300W:s blown out of the roof instead of exhausting it into the case. On a cpu it makes less sense as tower coolers are pretty much exhausting the heat anyways as there are exhaust fans next to the tower.

[jones177]

Yes.

 

Mainly because the AIO "standard setup" interferes with exhaust flow. 

 

One of the problems is it is different from case to case even though the cases may look similar.

 

The Noctua nh-d15 in the computer that is on the table about 30" away from me has 140mm fans and is usually silent. It also moves air across the 3080s backplate keeping it cooler than it would be on most AIO setups. Even overclocked and using 450 watts the 3080 stays relatively cool. 

The D15 pulls the hot exhaust from the GPU toward the exhaust fan and out of the case and only adds about 2c to the CPU temps.

 

With an AIO on top the fans are too far a away from the GPU to effect it and the air going from the top front fans to the AIO can block the hot air from the GPU exiting the case fast enough to keep it cool. 

 

For me that started with 2080 ti since the GTX 1080 tis have no problems in a standard cases with traditional air flow setups. 

The RTX 2080 tis ran hot but adding fans seemed to do the trick.

With 3080s tis and 3090s things fell apart since the 3080 tis put out as much heat stock as a 2080 ti does overclocked.

Without GPU fans at 100% hot air gets trapped below the GPU so the GPU recycles its own hot air. One of my solutions it to put an exhaust fan below the GPU but this worked with one of my cases be not another.

Easy to test. The glass below the GPU will get warm, then hot. With proper airflow the glass will stay cool.

 

The only CPUs that I have that really need the 360mm AIOs are the i9 10900k and i9 10900kf and the other two may go back to air.

 

I have had a new case with an AIO totally fail with 3080 ti so I am rethinking cases all together.

 

My last case I bought was a lian li o11 dynamic. I have the fans setup so that all the fans above the GPU are exhaust and all the fans below the GPU are intake. This is almost 10c on a 3080 ti compared to a traditional AIO setup in a Corsair 5000D.

 

It is really a GPU issue but I would rather spend a bit an a case and some fans than to rip apart a $2000 GPU that has no replacement if things go wrong. 

[thrasher_565]

5 hours ago, jones177 said:

Yes.

 

Mainly because the AIO "standard setup" interferes with exhaust flow. 

 

One of the problems is it is different from case to case even though the cases may look similar.

 

The Noctua nh-d15 in the computer that is on the table about 30" away from me has 140mm fans and is usually silent. It also moves air across the 3080s backplate keeping it cooler than it would be on most AIO setups. Even overclocked and using 450 watts the 3080 stays relatively cool. 

The D15 pulls the hot exhaust from the GPU toward the exhaust fan and out of the case and only adds about 2c to the CPU temps.

 

With an AIO on top the fans are too far a away from the GPU to effect it and the air going from the top front fans to the AIO can block the hot air from the GPU exiting the case fast enough to keep it cool. 

 

For me that started with 2080 ti since the GTX 1080 tis have no problems in a standard cases with traditional air flow setups. 

The RTX 2080 tis ran hot but adding fans seemed to do the trick.

With 3080s tis and 3090s things fell apart since the 3080 tis put out as much heat stock as a 2080 ti does overclocked.

Without GPU fans at 100% hot air gets trapped below the GPU so the GPU recycles its own hot air. One of my solutions it to put an exhaust fan below the GPU but this worked with one of my cases be not another.

Easy to test. The glass below the GPU will get warm, then hot. With proper airflow the glass will stay cool.

 

The only CPUs that I have that really need the 360mm AIOs are the i9 10900k and i9 10900kf and the other two may go back to air.

 

I have had a new case with an AIO totally fail with 3080 ti so I am rethinking cases all together.

 

My last case I bought was a lian li o11 dynamic. I have the fans setup so that all the fans above the GPU are exhaust and all the fans below the GPU are intake. This is almost 10c on a 3080 ti compared to a traditional AIO setup in a Corsair 5000D.

 

It is really a GPU issue but I would rather spend a bit an a case and some fans than to rip apart a $2000 GPU that has no replacement if things go wrong. 

30xx gpus should have bottom intake imo. having front intake is not enough. i be leave there wider and longer too but i dont no. and a back fan is a must have.

[Kazualty]

7 hours ago, Jeppes said:

Aio:s are great for gpu:s. Its nice to have that +300W:s blown out of the roof instead of exhausting it into the case. On a cpu it makes less sense as tower coolers are pretty much exhausting the heat anyways as there are exhaust fans next to the tower.

Of course if you assume you have no exhaust fans then yes the aio is great. But if you have exhaust fans instead (or use the setup I mentioned in OP) then you end up with more air being moved through less restriction. 

 

The setup I mentioned in OP also prevents loss of fresh air. Much is lost from the front getting sucked into the exhaust before passing components. Same happens with AIO rad when front intake is lost to top exhaust. If you have it set to intake instead with top-back blocked off (and a air cooler) you end up creating a front to back flow with a direct fresh intake for big air cooler (top-front) and still 3 unrestricted fans moving fresh from front (depending on case of course but most are similar nowadays). You should theoretically always get better gpu temps on good air cooling. No metal mesh wall

[jones177]

48 minutes ago, thrasher_565 said:

30xx gpus should have bottom intake imo. having front intake is not enough. i be leave there wider and longer too but i dont no. and a back fan is a must have.

They put a lot of heat into a case. 

It is to the point to were the traditional GPU and case designs are not working.

I am even looking at using a Thermaltake Core P3 ATX for my next build.

 

[thrasher_565]

9 hours ago, jones177 said:

They put a lot of heat into a case. 

It is to the point to were the traditional GPU and case designs are not working.

I am even looking at using a Thermaltake Core P3 ATX for my next build.

 

ya i have yet seen a gn video about it...thow many people on here were having hi temps.

 

i tryed to get a AMD Radeon HD 6990 for a poor mans hot gpu...i lost the bid by $5 well out bid by $5 no idea how hi it would have gone...had a water block too.

 

was looking in to an fx 3560 or w/e thow hot cpu were but man they want alot for it...

Edited September 27, 2021 by thrasher_565