3900x Temps

[BrainBug]

Hey Guys,

 

I recently made a 3900x build together with a Gigabyte x570 Elite and a Noctua NH D-15 , but it kinda bugs me when i check the temps on the CPU.

 

In Idle is stays around 37-41  degrees  (Celsius) , in load i couldn't get it past 77-78 max  (for a few mins , will try for a full hour to have a more better overview on stres test temps) 

 

My curiosity is the following thing, when staying in idle, litterally not doing anything i see the temps spike from 40 to 51 degrees , the fans start running for a few sec then it cools down and repeats the same thing after like 1-2 mins.

 

Is this Normal behaviour on this 7nm architecture?  Or should i be worried / should i take down the cooler and apply the thermal paste one more time ?

 

Thanks. 

[Bombastinator]

Sounds like AMD alright.  Ryzen2 did some weird stuff with boost and auto overclock and they’ve been messing with it for a while.  Normal with a new system.  Ryzen2 seems to be optically shrunk ryzen plus mostly, but they went to chiplets and completely changed boost and overclock.

[Zando_]

Normal behavior for Zen 2 chips. 

 

5 minutes ago, Bombastinator said:

Ryzen2 seems to be optically shrunk ryzen plus mostly, but they went to chiplets and completely changed boost and overclock.

It's Zen 2 (Ryzen 2 was the 2000 series which is Zen+), not sure what optically shrunk means either? OG Ryzen was on chiplets IIRC as well, and the boost/OC are the same. Just all chips have PBO now and it's improved a bit, but it still works the same. 

[Bombastinator]

Just now, Zando Bob said:

Normal behavior for Zen 2 chips. 

 

It's Zen 2 (Ryzen 2 was the 2000 series which is Zen+), not sure what optically shrunk means either? OG Ryzen was on chiplets IIRC as well, and the boost/OC are the same. Just all chips have PBO now and it's improved a bit, but it still works the same. 

Huh.  I thought ryzen+ was monolithic die.  Caught by the zen/ryzen number thing again.  Thanks

[BrainBug]

Then... i shouldn't worry about the sudden spikes? was running y-cruncher since ~20 mins ago, temps didn't pass 82 with load on 100% load on all cores and it seems to be stable around 67 degrees on 100% of max fan speed. 

 

Tho a weird thing is sometimes spikes up to 80 degrees and jumps back down in a mater of seconds, which takes me a bit to believe maybe there is some kind a glitch with the sensors sometimes?  Because the drop is way to fast to get cooled over 10 degrees for example or in idle from 41 to 62 sometimes i see spikes for example....

[Zando_]

1 minute ago, BrainBug said:

Then... i shouldn't worry about the sudden spikes? was running y-cruncher since ~20 mins ago, temps didn't pass 82 with load on 100% load on all cores and it seems to be stable around 67 degrees on 100% of max fan speed. 

 

Tho a weird thing is sometimes spikes up to 80 degrees and jumps back down in a mater of seconds, which takes me a bit to believe maybe there is some kind a glitch with the sensors sometimes?  Because the drop is way to fast to get cooled over 10 degrees for example or in idle from 41 to 62 sometimes i see spikes for example....

They hop around a lot lol, AFAIK that's also normal. The voltages can change very rapidly based on whether it's boosting cores, and if so then how much and how many. Temps can drop very rapidly with changing load even at a static voltage and clock (my 5960X runs static on both and if I put it under full load then stop it'll drop over 10C almost instantly). 

@Den-Fi has a lot more experience with the Zen 2 chips, both AM4 and TRX40, he can confirm for sure. 

[DildorTheDecent]

43 minutes ago, BrainBug said:

Is this Normal behaviour on this 7nm architecture?  Or should i be worried / should i take down the cooler and apply the thermal paste one more time ?

This is normal for Zen 2.

 

If the spiking annoys you try and configure a custom fan curve. Might help eliminate it.

 

10 minutes ago, Zando Bob said:

G Ryzen was on chiplets IIRC as well

yesbutactuallyno.jpg. A chiplet in terms of Zen 2 contains just the cores and cache. I/O such as the memory controllers is contained on the I/O die.

 

With Zen and Zen+ the cores and I/O were contained on one die. It was never referred to as being a chiplet officially IIRC. Just like a "normal" CPU. If you had many cores, you would have more than one die with the cores and supporting I/O.

 

Infinity Fabric links everything together.

[Guest]

Yeah. This is pretty normal. I have 2 3950Xs, 2 3900Xs, and a 3970X at home and it's normal. As well as over two dozen 3rd gens in the office.

[BrainBug]

I was thinking maybe the CPU Vcore being set on normal (was Auto previously)  may have any impact on the temps ? 

How do you guys set up the Vcore? Manual/auto/Normal ? 

 

Also having the PBO as enabled does it bring any improvements for any of you if it's on auto ? because i haven't seen any diference in Cinebench R20 with it disabled or enabled....

 

Max Voltage i have seen when monitoring the CPU was somewhere around 1.47 which looks a bit to big from what i understood, maybe this is the reason it's heating so fast sometimes. 

[ewitte]

It isn't idle windows is doing something in the background.  Even if its for a millisecond the CPU is responding.

 

[BrainBug]

Yeah , i know what you mean ewitte, but i meant regarding the spikes it does when just idling and if the voltage of 1.47 is a safe voltage?  Or if i should be worried about.

[alyen]

14 hours ago, BrainBug said:

Yeah , i know what you mean ewitte, but i meant regarding the spikes it does when just idling and if the voltage of 1.47 is a safe voltage?  Or if i should be worried about.

I assumed that fluctuating around 1.40-1.47V is safe, but am concerned when I read some people did static overclock with 1.40V and burned out the chip. I try to get enough apps running in the background, and often a MMO I play running with several clients just to keep the voltage down. I thought maybe it was because I was on B450 board at first but everything you describe is what I have been seeing the last 2 months. I had to set the lowest starting temperature for the fans around 58 C so I don't get the fans ramping up and down while doing light tasks and gaming.

 

You could also try underclocking or set it at 3.9 GHz manually with lower voltage if you are worried about it.

[BrainBug]

Underclocking wouldn't sound reasonable in my case , PBO set to Auto and CPU Vcore also to auto seems to be better than disabling or messing with voltage / other settings.

To be honest got better score with the settings on auto in Cinebench R20 (~7200) than with the settings and tweaks i was reading in other places where they were saying you can increase the performance up to 10% with the right settings and keep it also cool...

So far it i've seen it once, the other day go up to 80 after more then one hour of CPU stres... it's kinda annoying hearing the fans going up and done all of a sudden, but after a while you get used to it. 

[alyen]

 

I agree with leaving it on PBO. It was only a suggestion if you were concerned about and voltages being too high. I have 3 different fan profiles I use depending on what I'm doing mostly for the day. This is what I set my temperature ranges at.

 

Temp 1: 58 C - Slient while Idle and light tasks

Temp 2: 64 C - Quiet fans but runs a little cooler.

Temp 3: 68 C - Heavy CPU usuage Blender rendering, Prime95.

Temp 4: 78 C - I've neer it get here incase things do over heat

 

There doesn't seem to be a need to set the starting temperature so low and have the fans ramps up just because temps go to 54 C for a second while idle. My temperatures seem to reach around 69-72 C at full load so it seems to be tuned up to how I like it. You may want to find something that works for you.

 

 

 

[ewitte]

1.4x volts with a heavy load is way different than 1.4x volts without a load.