Fan hub / airflow question

[littlegreen]

Hi!

 

I am running a 7700k with a Noctua NH-D15 and it runs quite hot, but also GPU runs toasty especially in some titles.

I have a Kraken X73 I want to swap around to see if I can help the situation, as it will allow fresh air to flow through the case - hopefully the rad helps the CPU and the imrpoved(?) airflow helps the GPU.

 

So here's the issue I am having with the fans:

1. I have 1 CPU, 1 Pump and 2 chassis fans connectors on the motherboard in total.

2. Current setup is the 2 noctua fans are connected to the CPU and Pump respectively, and everything else is chassis fans front and back.

3. The Kraken has a pump and 3 fans that need connecting and I only have 2 available connectors.

 

I have never used fan hubs, and from my little knowledge in anything to do with voltages and currents, I know that daisy-chaining the rad fans will drop their maximum RPM by a lot. So I want to use a fan hub, but descriptions are vague at best, suggesting only 1 fan can be controlled by the motherboard directly - so I'm really confused - are the rest of the fans going to spin at max rpm the whole time?

 

Better yet - can someone suggest to me a simple fan hub that takes reading from the motherboard and dictate the same thing to all connected fans? I want to connect that to the CPU fan header and then connect the three rad fans to that, and leave the Pump header to the pump... that makes sense, right?

 

Thanks!

[Bombastinator]

I’m a bit confused.  I’m seeing both water cooling and air cooling terminology?  Also there a fan on a pump?  Maybe I’m just not getting it.  As far as the fan hub thing goes, the issue is that “a lot” is quite variable, and since a fan uses barely a third of the amperage a single port puts out I doubt that “a lot” will make a huge difference.  I could be wrong.
 

what I originally wrote thinking you had a standard air cooler for the cpu:
A dh15 is already a lot of cooler for a 7700k.  Makes me wonder if it’s a case airflow issue.  Putting on an AIO would change the airflow, so if you’ve already got it it’s a free option.  If you need to buy it though, first try opening the side panel on your case, point some air at it, and see if temps improve.  Might also be a mount issue, in which case again the AIO gives you another shot at mounting, but if you have to buy it remounting the dh15 would do more or less the same thing. 

Edited December 11, 2021 by Bombastinator

[OhioYJ]

50 minutes ago, littlegreen said:

I am running a 7700k with a Noctua NH-D15 and it runs quite hot, but also GPU runs toasty especially in some titles.

I have a Kraken X73 I want to swap around to see if I can help the situation, as it will allow fresh air to flow through the case - hopefully the rad helps the CPU and the imrpoved(?) airflow helps the GPU.

 

So here's the issue I am having with the fans:

1. I have 1 CPU, 1 Pump and 2 chassis fans connectors on the motherboard in total.

2. Current setup is the 2 noctua fans are connected to the CPU and Pump respectively, and everything else is chassis fans front and back.

3. The Kraken has a pump and 3 fans that need connecting and I only have 2 available connectors.

 

I have never used fan hubs, and from my little knowledge in anything to do with voltages and currents, I know that daisy-chaining the rad fans will drop their maximum RPM by a lot. So I want to use a fan hub, but descriptions are vague at best, suggesting only 1 fan can be controlled by the motherboard directly - so I'm really confused - are the rest of the fans going to spin at max rpm the whole time?

 

Better yet - can someone suggest to me a simple fan hub that takes reading from the motherboard and dictate the same thing to all connected fans? I want to connect that to the CPU fan header and then connect the three rad fans to that, and leave the Pump header to the pump... that makes sense, right?

 

Thanks!

 

So you have several things going on at once I think.

 

1.  I've run a 7700k with a NH-D15. The NH-D15, will keep it plenty cool. In fact when I passed this 7700k down to my son, I kept the NH-D15 and it's now cooled by a EVO 212. I'm with @Bombastinator I also wonder if you have enough case airflow, or a mounting issue. What are your temps? I've also seen motherboards overvolt these chips causing temperature issues. I know the one I had originally had an issue with this, until they issued a BIOS update for it.
2.  With fan hubs it depends on what you buy. Some just supply power to all fans, and they do run at full speed. Don't buy these. Some have manual controls, also not preferred in my opinion. I would get a PWM hub, that forwards the signals to all fans, so they will be controlled by the motherboard. Also keep in mind generally you can run two fans per header safely. So another option would be fan splitters if you didn't want to use a hub.

 

[Bombastinator]

12 minutes ago, OhioYJ said:

 

So you have several things going on at once I think.

 

1.  I've run a 7700k with a NH-D15. The NH-D15, will keep it plenty cool. In fact when I passed this 7700k down to my son, I kept the NH-D15 and it's now cooled by a EVO 212. I'm with @Bombastinator I also wonder if you have enough case airflow, or a mounting issue. What are your temps? I've also seen motherboards overvolt these chips causing temperature issues. I know the one I had originally had an issue with this, until they issued a BIOS update for it.
2.  With fan hubs it depends on what you buy. Some just supply power to all fans, and they do run at full speed. Don't buy these. Some have manual controls, also not preferred in my opinion. I would get a PWM hub, that forwards the signals to all fans, so they will be controlled by the motherboard. Also keep in mind generally you can run two fans per header safely. So another option would be fan splitters if you didn't want to use a hub.

 

I thought it was 3, which is why they make 3 way splitters. May be one of those variable things.

[littlegreen]

 @Bombastinator I think the confusion lies with what I said regarding the pump header on the motherboard. So my NH-D15 has 2 fans - connected to the CPU and Pump headers on the motherboard respectively.

 

1. I have 1 CPU, 1 Pump and 2 chassis fans connectors on the motherboard in total.

1. I have 1 CPU, 1 Pump and 2 chassis fans connectors on the motherboard in total. 
2. Current setup is the 2 noctua fans are connected to the CPU and Pump respectively, and everything else is chassis fans front and back. 

This refers to headers on the motherboard. CPU header and PUMP header. So the two Noctua fans on the air cooler are connected to those headers, not to an actual pump. I can see how the original post can be confusing, sorry!

 

 

@OhioYJ fan splitters would be OK for two fans, yes - but the AIO I want to use is a 3x120mm so there would be a drop in voltage, I believe?

 

Here is a picture of the current setup. The case(ASUS TUF GT501) is rather spacious - but especially with the side panel on, and combined with my ever-lasting lazyness of mounting the GPU vertically on a riser, you can see how an air-choke is bound to happen once the system gets under load. I'm hoping that with the X73 mounted across the top, the situation will improve noticeably.

 

P.S. I already have the X73 so it's simply a matter of choice.

 

[littlegreen]

@OhioYJ

 

I think the PWM Hub you linked to is what I need. I will have a look over at the UK Amazon to find an equivalent and .... ahem... release the kraken

 

EDIT:

Oh, and by the way - the 7700k is delidded and with Kryonaut between the chip and IHS - and with the NH-D15 gets up to 90 and stays there under load ALL the time... I've tried remounting a  couple of times and it does not seem to help one bit.

[littlegreen]

So I'm thinking of this as an option:

 

https://www.amazon.co.uk/ARCTIC-Pro-Gen-Ultrawide-Adjustment/dp/B087FY5CNT/ref=sr_1_4?keywords=mwp+fan+hub&qid=1639222379&sr=8-4

 

Looks like it will read the RPM requirement as set in BIOS from the motherboard and transfer the same RPM to all the fans connected.... I think

 

I'll report back tomorrow when it arrives alongside some thermal paste, as I've run out.

[OhioYJ]

2 minutes ago, Bombastinator said:

I thought it was 3, which is why they make 3 way splitters. May be one of those variable things.

 

Most of the time the number that gets thrown around is it's safe to run up to 1 amp on a single fan header (just because this was a common spec for some boards IIRC). Some motherboard manufacturers actually do list a rating in their manuals. Most don't. Some will give you a limit if you call them.  So it would actually depend on the fan. This is why I've always heard 2, as generally even if someone hooks up a high speed, or a generic cheapo fan, or has a cheap motherboard, they generally won't exceed this limit. Current draw is all over the place as well. The cheap 120mm Arctic fans people recommend regularly (not saying they are necessarily bad), draw twice what 120mm Noctua fan draws spinning a similar speed. Hence why it depends.

 

15 minutes ago, littlegreen said:

 

@OhioYJ fan splitters would be OK for two fans, yes - but the AIO I want to use is a 3x120mm so there would be a drop in voltage, I believe?

 

 

 

If you use fan splitters I would recommend using two of them, for the AIO. Just hook two of the fans to the CPU, and one fan and the pump to the pump header (ensuring that pump is one hooked to the signal line in the splitter).

 

[Bombastinator]

Ah.  You could get away with putting both cpu fans for the noctua on the cpu header I think. That would free up a header. Could then put two fans on the top for air out and not have to change the cooler.  Need a y connector or 2 and the fans to put in the top of the case. If one didn’t come with your cooler or it’s no longer around or you don’t also have spare fans it may not be worth doing.  A few fans and a y connector are cheaper than an AIO though. 

 

That looks like a fairly standard air cooling setup. Makes me wonder how impinged the front air intake is.  Pics say some but probably  not a lot.  Air does turn a corner and go through a grate, grate is big though and the corner isn’t 90°.  If the included fans are high static pressure that shouldn’t be a problem.  They might not be though, in which case someone at asus needs to be slapped with something.  This thing shouldn’t be as hot as you are saying it is.   Everything is relative though.  Your hot may be really cool for someone else. 

[OhioYJ]

33 minutes ago, littlegreen said:

EDIT:

Oh, and by the way - the 7700k is delidded and with Kryonaut between the chip and IHS - and with the NH-D15 gets up to 90 and stays there under load ALL the time... I've tried remounting a  couple of times and it does not seem to help one bit.

 

Kryonaut? That will not give you good results. That's why it's hot. So I delidded mine, kind of wish I never did. I experimented with all sorts of things, even an all Copper IHS. I forget what results I had I tried Kryonaut and Arctic silver between IHS and die, and I can't remember if it was worse, or about the same. You need Conductonaut (liquid metal) between the IHS and chip. It's not an exact science and it may take a few attempts to get the absolute best results.

 

So my 7700k stock ran

65 C in Cinebench

81 C in Max heat / power Prime 95

 

Delid with Conuctnaut

56 C in Cincebench

62 C in max heat / power Prime 95

 

That was back in 2018, as I mentioned it's under a 212 EVO now at my inlaws house, still running good temps. I haven't touched it.

 

**Edit** Want to make sure I add, Kryonaut between the chip and heatsink, absolutely, great idea. Kryonaut is great stuff. Just not good for under the IHS. under the IHS you will need liquid metal to improve temps.

[littlegreen]

@Bombastinator I think from reading @OhioYJ's posts it may be a thermal paste issue... or it may be a bit of everything, I suppose.

 

I happen to have some Conductonaut so when the fan hub arrives and I shut the machine down I will just take the IHS off and replace with that. I have not sealed the IHS with Silicone, so it won't be like I'm delidding all over again. I will do some benchmarking to get a baseline temperature - though not sure if there's a point since I will be replacing the cooler as well so it won't be a fair comparison...

 

@OhioYJ

I remember reading here on the forums quite a while ago that MX-4 was a big improvement over the factory-used stuff, and, if one didn't want to risk it with liquid metal they could use that instead - where it would be improving very nicely on the situation(not as well as liquid metal, but still) without the involved risks the Thermal Grizzly comes with. I just assumed that MX-4 or Kryonaut wouldn't be much different, but I guess there's much more to learn hehe. Thank you for the advice - I would have not even considered that.

[thrasher_565]

the d15 use to come with a 2 fan splitor in the box...if you got it new that is

[littlegreen]

@thrasher_565

I did get it new and it did have it - there was two of them, actually! ... but I had to give that away to the wife, as her new case came with 3 front fans and no splitters - and the motherboard did not have enough headers for chassis fans...

[thrasher_565]

8 minutes ago, littlegreen said:

@thrasher_565

I did get it new and it did have it - there was two of them, actually! ... but I had to give that away to the wife, as her new case came with 3 front fans and no splitters - and the motherboard did not have enough headers for chassis fans...

ok got it. ya one i think is a low speed one. ya they make a powered hub if you think your go over the mb header limit. you can also make your own by hooking the power to the psu and tac and pwm up to the mb. from what i read it can do about 10 fans and pwm dose get weeker.

[littlegreen]

(facepalm) I wish I thought of that before I ordered the PWM fan control unit LoL!

[Bombastinator]

3 minutes ago, littlegreen said:

(facepalm) I wish I thought of that before I ordered the PWM fan control unit LoL!

Might still be able to cancel if it hasn’t shipped. 

[littlegreen]

1 hour ago, Bombastinator said:

Might still be able to cancel if it hasn’t shipped. 

Amazon same-day delivery... way too late it was only 8 quid, so not the end of the world... besides I'm waiting on the Kryonaut for the AIO anyway... 

[OhioYJ]

5 hours ago, littlegreen said:

@OhioYJ

I remember reading here on the forums quite a while ago that MX-4 was a big improvement over the factory-used stuff, and, if one didn't want to risk it with liquid metal they could use that instead - where it would be improving very nicely on the situation(not as well as liquid metal, but still) without the involved risks the Thermal Grizzly comes with. I just assumed that MX-4 or Kryonaut wouldn't be much different, but I guess there's much more to learn hehe. Thank you for the advice - I would have not even considered that.

So when I was experimenting with delidding all the overclocking forums, and stuff I read pretty much indicated there was no thermal paste that gained anything. Which was pretty much what I found out as well. I tried a coupled different compounds, and gave up and went liquid metal. IIRC it was liquid metal, or leave it alone.

 

There is only a few pins under the IHS anyways, so liquid metal isn't a big deal on the 7700k. Just use some clear nail polish and cover them up. (my 7700k)

 

 

I keep waiting for that PC to do something funny. It's in a vertical position, and it's been going for over 3 years now, temps are still great. I figure I'll leave it alone till the temps change. It is being cooled now with a EVO 212, but it is a lapped 212 (My NH-D15 went to my new PC).

[WoodenMarker]

16 hours ago, littlegreen said:

I have never used fan hubs, and from my little knowledge in anything to do with voltages and currents, I know that daisy-chaining the rad fans will drop their maximum RPM by a lot.

15 hours ago, littlegreen said:

@OhioYJ fan splitters would be OK for two fans, yes - but the AIO I want to use is a 3x120mm so there would be a drop in voltage, I believe?

No, voltage and max rpm wouldn't drop. The fans will draw as much power as needed. Depending on the motherboard, a header can usually support up to 1A or more. If the fans don't draw much power, 3 or more fans can easily run off of a single motherboard fan header. 

The Kraken X73 fans are rated at 0.18A each and NF-A15 at 0.08A 3 fans can easily run off of a fan header that supports up to 1A. 

15 hours ago, littlegreen said:

Oh, and by the way - the 7700k is delidded and with Kryonaut between the chip and IHS - and with the NH-D15 gets up to 90 and stays there under load ALL the time... I've tried remounting a  couple of times and it does not seem to help one bit.

Liquid metal or something similar is needed on the bare die when delidding. Normal thermal paste will pump out with thermal cycling in a week or two and result in similar or worse cooling compared to no delid at all.