[SOLVED] What is a *normal* temperature for Ryzen 9 3900x?

Blueblack

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Mar 25, 2019
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I’m just playing around with the settings for my new build system ... and as I build my last PC around ten years ago, I feel quite like a newbie in many things now ...

So, I am wondering, what‘ would be a normal temperature for my CPU? ... I have read a lot of threads, where people are unsure, if even 40-50 °C would be too hot ... but my CPU is around 60-65°C on idle ... best I get is 59°C with all fans full speed atm ...

Sure, I have an ITX build and everything is air cooled (3 case fans + and a Noctua Chromax for the CPU) ... ofc, I could slap in another two fans or maybe get water cooling ... or even a bigger case ... but on the other side, when I look at the AMD Balanced Power Plan in Win 10 I‘m actually wondering ... minimum CPU performance is set to 99% and max performance to 100% ... ??? ... maybe I‘m just dumb, but what‘s the sense of such a ‚balanced‘ power plan?

Btw, I don’t plan to oc things and usually I don‘t play very demanding games ... atm the system is (beside the GPU, which I already had) actually somewhat overpowered for my needs ... but bc of all that, I simply don‘t want to stress my CPU just for nothing ...

Sorry for this wall of text ... but I would be glad to hear your opinions/ideas on the matter of my CPU temp ... many thx!

Edit: checked the temp now in Win10 with HWMonitor ... it shows the CPU temp between 33°C min and 62°C max ... atm 36°C on idle with all fans on silent setting ... so the problem looks not so critcal ;)
 
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Solution
The U12S isn't really capable enough for the 3900x. That CPU really NEEDS a better cooler, especially in cramped quarters like that with little airflow.

Try adding another exhaust fan in the top rear location of the case. One exhaust fan really isn't enough for ANY tower style case, whether short, tall, fat, or otherwise, when using high end hardware. Exhaust fans are far more important when it comes to cooling performance than intake fans, but intake fans matter as well because you NEED to get a resupply of cool air into the case, but you also NEED to get an equal amount of hot air OUT of the case AS that cool air is coming in, or else it literally does no good to bring it in at all.

That might help your CPU cooler somewhat. A lot...
Idle temperatures normally "don't matter", at all. If you had a 70°C idle temperature but a maximum full load-steady state temperature of 80°C while running Prime95 Small FFT with all AVX instructions disabled (Or OCCT small data set), then that 70°C temperature would be irrelevant. If however your maximum temperature while under a full load was higher than 80°C, THEN that idle temperature would be representative of a problem.

In your case, I could just about tell you that having a 60-65°C idle temperature IS a problem, simply do to the configuration.

There are a few things you probably need to do, first, but before that, exactly WHICH Noctua CPU cooler do you have?

What case model do you have?

Where are your case fans installed and are each of them in an intake or exhaust orientation?

DO you have the latest motherboard BIOS version installed?

Do you have the MOST recent AMD chipset driver from the AMD website installed for your motherboard, which you did not bother to list, and what are your FULL hardware specifications including ALL part/model numbers?

And for now at least, I'd probably change that power plan to the regular "balanced" plan and make sure that the minimum processor power state is set to 5% and the maximum to 100%.

Also, make sure all of these are set accordingly in the BIOS.

Cool N Quiet - Enabled

Core CPPC - Enabled

CPPC preferred cores - Enabled

Advanced/Global C-states - Enabled

Precision boost overdrive (PBO/PBO2) - Disabled. Also, standard boost profiles like Precision boost (Non-overdrive) and XFR2 should be left enabled.)
 

Blueblack

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Mar 25, 2019
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@Darkbreeze
sorry, forgot to list the specs ...

Case: Fractal Define Nano
CPU Cooler: NH-U12S
MB: Asrock B550MPro4 ITX/ac
GPU: Sapphire Radeon RX 580 8Gb
RAM: 32Gb 2133 Mhz
PSU: bequiet SFX-L 600W
1 rear fan 120mm out, 2 front fans 140mm intake

All drivers are up to date ...
 
The U12S isn't really capable enough for the 3900x. That CPU really NEEDS a better cooler, especially in cramped quarters like that with little airflow.

Try adding another exhaust fan in the top rear location of the case. One exhaust fan really isn't enough for ANY tower style case, whether short, tall, fat, or otherwise, when using high end hardware. Exhaust fans are far more important when it comes to cooling performance than intake fans, but intake fans matter as well because you NEED to get a resupply of cool air into the case, but you also NEED to get an equal amount of hot air OUT of the case AS that cool air is coming in, or else it literally does no good to bring it in at all.

That might help your CPU cooler somewhat. A lot actually. Also, if your case has the removeable top covers I'd leave them in place except for the one in the back where you'll be adding a fan, if you add a fan. I think it would be wise to do so.

I think it would also be wise to run a thermal compliance test and see if you are in fact compliant or not.



Testing thermal compliance


Once you get to the Windows desktop, the first thing you will want to do is open HWinfo (Sensors only option), Core Temp or Ryzen Master and take a look at what your core and package temperatures are doing. At idle your core temps should be somewhere below 40°C in the majority of cases. Preferably somewhere in the mid to low 30’s. On some newer very high core count models, or if you are using the stock cooler (In which case you shouldn't be overclocking anyhow), then it might not be below the 40°C threshold.

If you are not overclocking and are ONLY testing the thermal compliance of the stock configuration, then don't be TOO concerned by a high idle temperature UNLESS you also have a high load temperature that is outside of spec. This WILL be affected by whatever the ambient temperature is in the room where you are, so if your are in a very warm region and have no air conditioning going you may have an idle temp that is a bit closer to 40. For cooler ambient rooms or regions it will likely show low 30’s-ish. Be aware that unless you have excessively high idle temps, say, above 40°C, then what your actual idle temps are is practically irrelevant. Cooler idle temps are not indicative of much of anything specific.

Very HIGH idle temps however DO indicate that there is likely a problem with an incorrectly installed CPU cooler heatsink, too high of CPU core voltage or some other cooling or voltage related issue. If you are using one of those other utilities I warned about in the beginning of this tutorial, it may also be that the utility is reporting falsely. In that case, go get HWinfo or CoreTemp and check again.

If idle temps seem fine, then leave your monitoring application open and run Prime95 (Either version 26.6 or the latest version with AVX/AVX2 disabled).

Choose the Small FFT option (NOT "Smallest FFT") and allow it to run for fifteen minutes. If you are using the latest version of Prime95 (Version 29.8 or newer) then you NEED to be sure to disable the AVX and AVX2 options in the main options window. When you disable AVX2 the option to disable AVX will become available. If at any point your core or package temperatures exceed 80°C for Intel or AMD Ryzen platforms, then click the “Test” menu at the top of the Prime95 window and select “stop” or “exit”. Do not simply click the "X" in the top right corner as that will NOT stop the stress test, it will only minimize it to the tray.

You MUST click Stop or Exit from the drop down TEST menu at the top left of the window to stop the stress test.


If you have an older AMD system that is pre-Ryzen, then measuring thermals is going to be a little different. If your AMD system IS a Ryzen based system, then testing will be the same as for Intel based systems.

On pre-Ryzen AMD systems they did not make, by any definition, measuring core temps accurate or reliable. On the low end of the scale their thermal sensor readings have long been laughable, sometimes showing temps that are well below what the ambient temperature is, which of course is not possible without some kind of Peltier cooler or active refrigeration. At the other end of the thermal range it’s not much better.

This is because AMD does not actually implement their sensor designs to be determined in the same way that Intel does. AMD uses a method known as distance to Tjmax. Tjmax being, in this case, the temperature at which AMD has determined bad stuff will start happening such as thermal throttling, shut downs and damage.

For this reason when you are testing thermal compliance, or just monitoring for general purposes, you need to be aware of this difference and purposely either use applications designed for use with AMD processors or make some settings changes in other utilities that will allow you to see distance to Tjmax rather than estimated core temps.

There are a couple of ways you can do this. First off, HWinfo generally has the appropriate fields which are labeled as Distance to Tjmax. I feel like the better choice though is either CoreTemp or AMD overdrive for monitoring Distance to Tjmax on AMD platforms. In CoreTemp you will need to go into the Options tab, click on Settings and on the Advanced tab check the box next to the setting for “Show distance to Tjmax in temperature fields” in order to change from the default and likely inaccurate core temperature display.

AMD overdrive shows Distance to Tjmax by default, and I don’t think there is any other way to monitor CPU thermals in that utility anyhow. Either of these is probably a good choice, but it’s also likely worth checking either CoreTemp or AMD overdrive against what you see for Distance to Tjmax in HWinfo and if the readings are pretty close to the same, just use HWinfo as there is a lot of other information available in the sensors display that is not available with these other two.

Regarding the actual Distance to Tjmax sensor readings, what you do NOT want to see is anything closer than 10°C Distance to Tjmax, ESPECIALLY if you are only in the first phase of your overclock configuration and have only made minor changes to the CPU multiplier and voltage at this point. If it drops below ten degrees to Tjmax you are getting very close to your thermal ceiling and need to revisit either your cooling solution or voltage settings.

If you can run the Prime95 version 26.6 or 29.8 (With AVX/AVX2 disabled) Small FFT (NOT "Smallest FFT". ONLY use the "Small FFT" for our purposes.) torture test for 15 minutes without exceeding 80°C for Intel/AMD Ryzen or dropping below 10°C thermal margin (AKA Distance to Tjmax) for AMD, then you are to some degree or other within specification for thermal tolerance.

It's important to note that when stopping or attempting to exit Prime95 that you MUST use the drop down file menu and choose either "Stop" or "Exit". Simply clicking the X in the top right corner like you would for most programs will not stop the test, and will leave it running in the system tray.

If you are very close to the edge however, this may be a warning sign that you don’t have much overclocking headroom since we’ve only barely set our multiplier to what is basically the all core equivalent of the default single core Turbo frequency (Speed). IF that is the case, you will want to either be very careful going forward or stop and think about upgrading your CPU cooler and perhaps looking at whether your case and case fan situation is really sufficient for what you are trying to do.
 
Solution

Blueblack

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Mar 25, 2019
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510
Thanks a lot for your tips! ... I will check things with HWInfo + Small FFT ... as it goes for the additional cooler; I have already a rear fan installed, so I only could put another 1-2 fans on top (which I actually want to avoid)
 
Yes, you don't NEED to put two additional fans. Just add ONE additional fan, to the top rear location so that you have a rear, a top rear, both as exhaust, and then two front intake fans. So you end up with two intake fans, bringing cool air INTO the case, and two exhaust fans, taking hot air OUT of the case. A nice balance, neither positive or negative, so get the benefit of better cooling from the negative pressure configuration and the dust suppression of the positive pressure, both to a slightly lesser degree but a good balance of each.

Certainly, should be plenty of airflow for that configuration and you do NOT want to use top exhaust fan locations with an air cooler that are middle or front locations because they will tend to "steal" airflow from the CPU cooler which forces it to use at least a partial mix of heated air rising from the GX card and PSU. You don't want that.