Question 3900XT fan speed up and down issue

Nov 10, 2019
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Dear all,

i have just mounted:

Ryzen 9 3900XT AM4
x570 - p motherboard
Noctua NH-U12S (read on some lectures it was fine for this cpu)

Coming from intel i7, i maintained my nvme.m2 hd. I am on linux, mainline kernel.

At first boot, all worked out of the box.
Only issue is that in dile, 1% cpu, i have cpu fan going up and down.

Right now, Tdie idle seems about 47

Fun control in bios is now "auto".

Every help is really appreciated.

angelo
 

Phaaze88

Illustrious
Ambassador
These cpus are completely different from the Intels you're used to, and even the older Ryzens. They 'love to bounce' on lighter loads; they don't behave that way when the load is heavy enough.
Auto curves are terrible on these cpus - not for thermals, but for some users' ears. Setting your own curve is a must.

Since you're also on an Asus board, try a more 'flat' curve. Something like the following:
Upper temp limit: 75C
Upper temp limit fan speed: 100%

Middle temp limit: 60C
Middle temp limit fan speed: 60%

Lower temp limit: 50C
Lower temp limit fan speed: 60%

It doesn't have to look exactly like that, but the point is to keep the lower and middle fan speeds the same.
 
Reactions: kurdtnz
Nov 10, 2019
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Hi Phaaze,

thanks a lot.

I tried your setup, keeping min and middle at 50%, but now i hear the same continuous variations (up and down every 5 seconds) from 50 to 100% or maybe a bit less than 100%.

So only difference is the starting %.
 
Nov 10, 2019
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Hi phaaze,

still thanks.

Well, increasing the minimum to 60% from 0 to 60*C helps but keeps fan noisy with cpu in idle.

I rolled back to auto settings and verified the idle temp for this cpu is quite high, 48 or 55 at 1% cpu with fan at 30%.

This is the second time i am not happy with a Noctua fan. I mounted it perfectly, repeated mount 3 times, as per manual, but the fact idle temp is higher than normal seems to indicate this fan/heater are not enough for this cpu.
Of course, i can be totally wrong.
 
Nov 10, 2019
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Hi Phaaze, thanks

i did some improvements:

removed NH-U12S .. and removing it, i realized cpu was remained attached to the heat sink ... Discovered this, in some panic, i re-plugged the cpu in the socket and all seems ok.

Then, i gave as much as possible air opening all windows of the case, put all 3 case fan positioned and running properly, changed heat paste to a cooling master i had here, remounted.

Now idle temp, checking from Bios, at 27 *C ambient, is 39 *C, so seems much better.

In linux with 0% cpu consumption, T idle seems 44, so quite good. Up and down of the fan are still there but seems a lot reduced. I can stay this way until i get / try a different heat sink.

Thanks a lot for now.
 

Zerk2012

Titan
Ambassador
Hi Phaaze, thanks

i did some improvements:

removed NH-U12S .. and removing it, i realized cpu was remained attached to the heat sink ... Discovered this, in some panic, i re-plugged the cpu in the socket and all seems ok.

Then, i gave as much as possible air opening all windows of the case, put all 3 case fan positioned and running properly, changed heat paste to a cooling master i had here, remounted.

Now idle temp, checking from Bios, at 27 *C ambient, is 39 *C, so seems much better.

In linux with 0% cpu consumption, T idle seems 44, so quite good. Up and down of the fan are still there but seems a lot reduced. I can stay this way until i get / try a different heat sink.

Thanks a lot for now.
Welcome to AMD they jump up and down all the time for really nothing.
 
Nov 10, 2019
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Hi,

just an update, since i have seen in the net a lot of users seems to have the same issue.

i noticed that bios settings of x570 was set to "asus optimal" (red image), i set it back to "normal" and now things are quite better.
Before, cpu frequency was fixed near 4000 Mhz, now it is changing from 2000 to 4000 as needed.

Fan speed up and down is really reduced sometime does not happen in minutes.
 
Reactions: Phaaze88
Nov 10, 2019
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Another update that may be useful.

Yesterday i did an internet-based bios update, it moved from 1407 to 2407. Today, checking asus website, there was a 2602 available with some "fan control" fixes. So more recent than the one found by automagic internet upgrade. Installed it, seems there is some improvement.

But still, in linux i see

idle, Tdie 39 tp 45
opening firefox, for a moment cpu goes to 70, then back to 45 in 2 seconds, fan immediately goes up and down.

Trying now to increment delays.
 
Nov 10, 2019
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There are some settable step up step down delays, that can be set on bios side, that seems not be considered under linux.

Such fast 45 -> 70 opening firefox enforces the above thought that the fan seems not the best.
 
Nov 10, 2019
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Still an update, likely the last before i upgrade my heatsink.

I found that for this Asus x570 Prime, some bios settings change works to fix the issue at 95% (some up and down of the speed is still audible but seems much more rare)

Disable "Precision Boost Override"
Disable "Core Performance Boost"

Hope this can help.
 

Phaaze88

Illustrious
Ambassador
Why buy the 3900x and turn PBO off?
For some users, it doesn't do much of anything, except make it run hotter. Auto actually works better for them.
I haven't suggested using PBO for some time because of that.

The single thread advertised boost frequency won't change, but some people seem really obsessed with multi-thread performance for whatever reason, significantly increasing power and thermals for so little, plus it's not always being used.
It's pretty dumb.
What do you do when some folks insist on going that route? I give up and go with the flow, or abandon thread.
 
Nov 10, 2019
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Well i am totally using all the 24 threads fully, for a big part of the day. There are not only gamers around interested in such cpu's. Due to this, i do my job in half of the time respect previous intel cpu.

I have seen AMD declare that is not selling anymore such cpu's with heat sink and cooler. Probably, because the fact thousand of users around the world seems to have this same exact issue, fan speed up and down continuously, that seems mainly due to an inappropriate cooler. For this reason, likely, AMD is suggesting in his site, 240mm liquid coolers for such cpu's.

Yes, i would re-enable the above options. Monday i'll receive one 240mm liquid offically suggested from AMD site in his list. And will report here how it will go.


Thanks again
 

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