How many fans? (and other queries)

[Nitefly]

Hi there.

Sorry for my crap noob thread.

I’m intending on building my first PC and treating myself so it’s a bit of a beast. I’ve always fancied being a nerd and overclocking

My intended build is going to more or less follow this chap’s with a Lian Li XL case. He’s running 12 (4 x 3) Lian Li sl120 fans as follows:

- 6 on a push/pull radiatior intake at the front/side of the case
- 3 intake at the bottom
- 3 exhaust at the top.

The CPU cooler will be something like an AIO Kraken Z73 (which the same chap installs on another video:

My build is likely to have a high end 5000 series Ryzen CPU and a 6800/6800 XT cpu. Go big or go home!

Aim: I want a cool looking fan set up for a high spec machine that can be set up and then ideally doesn’t need constant manual fiddling every day.

Query one: It looks really cool but is this amount of fans total and utter overkill in principle? 12 fans!!

Second query: Presumably the push/pull is to help those fans on the radiator run quieter... but you still have the other fans in the case which will need to be running at the higher speed....? I’m a bit confused as to whether in a set up like this you have fans blowing at different speeds.

Third query: Finally, I gather these Lian Li fans (which are the ones you connect together in sets of 3 with one cable) don’t have a fan curve and if the answer to the previous query is that the fans should run at different speeds, I may then need to manually change the fan speeds depending on what I’m doing... which sounds a bit crap? Is this a pain to do? Or is this an utter non event as it’s all sorted automatically by software?

Edit: actually I anticipate that the radiator fans are set on a quiet mode and the other fans in the case are on an automatic mode. Does that sound right / sensible?

If anyone can help this utter noob with these queries, I’d be really grateful.

I anticipate that it will all require a fair bit of experimentation when I build it, which I’m happy to do.

Thanks for your time.

 

[pp111]

No problem in having too many fans for show! But I would question whether you really need to have six on the radiator. That's a lot of cost for very little gain. You can't even see them. With that many fans I just put the radiator fans on water temp and the rest ( 3 top 3 bottom ) I link to the GPU. You may be able to do this with the motherboard or something like a Commander Pro.

 

[Nitefly]

No problem in having too many fans for show! But I would question whether you really need to have six on the radiator. That's a lot of cost for very little gain. You can't even see them. With that many fans I just put the radiator fans on water temp and the rest ( 3 top 3 bottom ) I link to the GPU. You may be able to do this with the motherboard or something like a Commander Pro.

Thanks mate, appreciate you took the time to read my post and respond.

Good idea re: linking the different sets of fans to different things. I guess there are quite a few options really.

 

[pp111]

Thanks mate, appreciate you took the time to read my post and respond.

Good idea re: linking the different sets of fans to different things. I guess there are quite a few options really.

Yep there is no one rule, everyone finds their own solution, but I have tried that particular solution and find it to be very good. You can happily drive all the fans from the CPU but I tend to find that when I play a game the CPU is not the thing under stress, the GPU is, so it's the GPU creating all the heat. But you may be different.

 

[ttaskmaster]

3 intake at the bottom

I always prefer to have bottom fans exhausting, as it draws less dust into your system.
I also dust my PC out around once a month though...!

Query one: It looks really cool but is this amount of fans total and utter overkill in principle? 12 fans!!

In a standard config I have six, but I'm abut to go Push-Pull, which will boost that up to eleven.

Second query: Presumably the push/pull is to help those fans on the radiator run quieter... but you still have the other fans in the case which will need to be running at the higher speed....? I’m a bit confused as to whether in a set up like this you have fans blowing at different speeds.

Push-pull is primarily to increase the performance on those radiators.
Gains can sometimes be minimal, or in other cases utterly astounding, all depending on how thick your rad is. Generally it won't make that much difference until your rads are around 45mm, and it's pretty much a requirement on the big 60mm ones.
However, depending on your rads again, it often does have the added benefit of being able to run far quieter.

The aim is to have all fans of the same make/model on both sides of the rad, so they run at identical speeds in order to give identical performance. Doing otherwise will cause problems and can even damage your fans.
Other fans in your system, like case fans, can be whatever you like and they'll generall be running at different speeds because they won't have to match the rad fans for performance and you'll certainly want them running quiet. I have my case fan on the back running slower as it doesn't have to work as hard and the noise is better.

Third query: Finally, I gather these Lian Li fans (which are the ones you connect together in sets of 3 with one cable) don’t have a fan curve and if the answer to the previous query is that the fans should run at different speeds, I may then need to manually change the fan speeds depending on what I’m doing... which sounds a bit crap? Is this a pain to do? Or is this an utter non event as it’s all sorted automatically by software?

Fan Curve just refers to how much the fans ramp up their speed as the system temperature increases. It's usually represented by a graph with points on it, which make a curve as you go along.

You can rely on the preset curves in the software, or you can create a curve yourself and then let the software run that. It's a minor fiddle to make your own, but once created and you're happy with it, it's set.
You can set all fans to run the one curve, do it in sets or, if you really wanted, have one curve for each and every single fan.
In short, it's all automatic and you can decide which setup gets run automatically.

Edit: actually I anticipate that the radiator fans are set on a quiet mode and the other fans in the case are on an automatic mode. Does that sound right / sensible?

That's one way to do it, but really noise is subjective and you may find a slight noise increase is something you can tolerate in return for increased cooling performance.

 

[Nitefly]

@pp111 yeah looks like it’s a case of setting to personal preference. Looking forward to it! Thanks again.

I always prefer to have bottom fans exhausting, as it draws less dust into your system.
I also dust my PC out around once a month though...!


In a standard config I have six, but I'm abut to go Push-Pull, which will boost that up to eleven.


Push-pull is primarily to increase the performance on those radiators.
Gains can sometimes be minimal, or in other cases utterly astounding, all depending on how thick your rad is. Generally it won't make that much difference until your rads are around 45mm, and it's pretty much a requirement on the big 60mm ones.
However, depending on your rads again, it often does have the added benefit of being able to run far quieter.

The aim is to have all fans of the same make/model on both sides of the rad, so they run at identical speeds in order to give identical performance. Doing otherwise will cause problems and can even damage your fans.
Other fans in your system, like case fans, can be whatever you like and they'll generall be running at different speeds because they won't have to match the rad fans for performance and you'll certainly want them running quiet. I have my case fan on the back running slower as it doesn't have to work as hard and the noise is better.


Fan Curve just refers to how much the fans ramp up their speed as the system temperature increases. It's usually represented by a graph with points on it, which make a curve as you go along.

You can rely on the preset curves in the software, or you can create a curve yourself and then let the software run that. It's a minor fiddle to make your own, but once created and you're happy with it, it's set.
You can set all fans to run the one curve, do it in sets or, if you really wanted, have one curve for each and every single fan.
In short, it's all automatic and you can decide which setup gets run automatically.


That's one way to do it, but really noise is subjective and you may find a slight noise increase is something you can tolerate in return for increased cooling performance.

Thanks mate. Lots for me to digest here.

Re: exhausting out of the bottom, and I say this as an utter noob, is that less efficient because of the old physics mantra that ‘hot air rises’? Appreciate the dust benefits.

Sounds like the software to run all of this is quite sophisticated, although those Lian Lin fans typically connect to their own controller which doesn’t allow a sophisticated fan curve, apparently. Not 100% sure, more reading to do clearly!

Thanks again, really helpful.

 

[ttaskmaster]

Re: exhausting out of the bottom, and I say this as an utter noob, is that less efficient because of the old physics mantra that ‘hot air rises’? Appreciate the dust benefits.

Thank you for not saying 'heat rises'!

Yes, hot air rises... but light a cigarette and watch as that hot air pushes the smoke upward. Then put a PC fan about four feet above, blowing air down and across the cig, whereupon you'll see that smoke blown straight down.
In short, the fan has more than enough oomph to overcome the rising heat!

Sounds like the software to run all of this is quite sophisticated, although those Lian Lin fans typically connect to their own controller which doesn’t allow a sophisticated fan curve, apparently. Not 100% sure, more reading to do clearly!

It looks like there are a couple of preset speeds/modes... but there's also a Sync setting, which looks to turn control over to the motherboard - That would mean setting up a curve in BIOS, or perhaps using something else, like perhaps SpeedFan.

 

[doyll]

Heated air is less dense and cooler heavier air move into the area of less dense air moving it up. But even the slightest forced (fan at idle) easily overpowers warm air from simply rising.

Most all motherboards have fan software for their fan headers with 4-8 temp to rpm points to setup curves.
I would set fan speeds
20% at 32c
40% at 60c
75% at 70c
100% at 75c
I set fan speeds to be inaudible up to about 60-65c, then ramp up to full speed by 75-80c.