Safe temperatures for my CPU 9 3900xt in my MAG B550 Tomahawk AMD Mb?

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I have The MAG B550 Tomahawk AMD mb, CPU Ryzen 9 3900xt, 32GB Memory, Asus Geforce GTX 1660 with 6GB memory video, 2 X WD Black 500GB M.2, one for OS windows 10 and one for storage. Also with masterliquid lite 240 CPU cooler. I can't find what is the safe temperature range for my CPU on the AMD website. Anyone know what is the highest temp this CPU should not run over? I am not OC this CPU, but, just running a bench test to get the numbers on my computer, I saw temps up to 93C and the test only ran for about 2 minutes or less. I tried to stress test it, but a few minutes into the test and I saw 102C and before I could turn the test off, my computer shut down by its self. I've never had an AMD CPU before, so I guessing that is way to high? The only thing that I have tried is to put the CPU core V form 1.400 on the mb to v1.250 but I didn't see any difference in temps, so I went to v1.200, but still didn't see any difference it temps. I did this because I saw it in several blogs, said to do this? am I right? Also in open hardware monitor it says all my CPU cores are running at 3800MHz all the time. Isn't this CPU suppose to run from 3800 to 4600? I would really appreciate if someone could help me understand the temps and also get this thing running at 3800 to 4600 under load like it is suppose to. Thanks You So Much, and God Bless You
 
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What exactly is your problem? Does your PC work, or doesn't it?
And why don't you want to run it with default values, if it works fine?
I just don't see the point here.
 
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That is what I’m trying to find out! Is 102C temp OK? And was that why my computer shut down on its own as soon as I saw that temp? Do you know what the sate temp is for my CPU? I’ve always worked with Intel CPUs before and in their spec for every CPU they tell you what their temp limit is. Why doesn’t AMD state this? It cost me over $450. So I can't afford to burn this one up. Yes when I use my word processor program my computer works great. I’ve even done a little video editing and everything seems OK, short videos only, I’m afraid to do very much. But I’ve read a lot of people doing stress test on their computers to make sure it is stable, but when I run one on my computer in less than two minutes it shuts its self down? (I mean the power goes off my computer.) Does that sound like it works fine to you? I don’t know, that is why I’m asking. The stress test that I use came with my MSI mb. Also when I use the bench test that came with my mb I see temps in the 93C. Is that normal? Also AMD advertized that this CPU runs at 3800MHz and boost to 4600MHz. Windows tells me it runs at 3800 all the time? Even the open hardware Monitor show it runs at 3800 all the time. Even when I run the bench test I only see 3800MHz. Is that normal? Are my temps keeping it from boosting? Thank you for your input and time, I appreciate it.
 
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It will not burn, because BIOS shuts it down. In your BIOS you can adjust at what temperature the system will shut down. I have a Ryzen 3900X with standard air cooling and the shutdown temp is adjusted to 95 degrees.
You will never reach these temperatures in any real world application, only in stress tests.
Stress tests are like driving your car for hours with the pedal down to the maximum. Nobody does this. And nobody worries if his car will break if you do this. Because it's no good idea. Just like stress tests for new CPUs.

If you really want to know how fast your CPU runs, why don't you use Ryzen Master? The only tool for this use. AMD designed this, because all other benchmark and monitoring programs had difficulties because Ryzen CPUs are too fast to monitor.
 

badboy2k

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i would check your Thermal Paste between the cooler and CPU as that temp sounds very high to me. 95C is the safe temp and above that is a sign of a problem.

also are you overclocking the CPU?
 
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It will not burn, because BIOS shuts it down. In your BIOS you can adjust at what temperature the system will shut down. I have a Ryzen 3900X with standard air cooling and the shutdown temp is adjusted to 95 degrees.
You will never reach these temperatures in any real world application, only in stress tests.
Stress tests are like driving your car for hours with the pedal down to the maximum. Nobody does this. And nobody worries if his car will break if you do this. Because it's no good idea. Just like stress tests for new CPUs.

If you really want to know how fast your CPU runs, why don't you use Ryzen Master? The only tool for this use. AMD designed this, because all other benchmark and monitoring programs had difficulties because Ryzen CPUs are too fast to monitor.
Thanks for letting me know about Ryzen Master, I’ll look for it and uninstall the other tools I got. Didn’t know other tools could have problems, thanks
i would check your Thermal Paste between the cooler and CPU as that temp sounds very high to me. 95C is the safe temp and above that is a sign of a problem.

also are you overclocking the CPU?
I’m not OC, not that knowledgeable, so I just want this computer to last a long time. Only thing I changed is the CPU core v, it was 1.400, I read a few forum than if you lowered v to 1.25 or even 1.200 that would lower the temps and maybe increase performance, but I didn’t see any drops in temps. Should I put it back to v1.400 which is default? I haven’t changed any other things in OC. Today I will take off the pump and clean it and install paste again to see if this helps. Thanks, I appreciate your input.
 
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I read a few forum than if you lowered v to 1.25 or even 1.200 that would lower the temps and maybe increase performance, but I didn’t see any drops in temps. Should I put it back to v1.400 which is default?
Undervolting limits the maximum CPU speed, so maybe this is the reason your CPU never boosts. Yes, I would definitely go back to default.
Good luck!
 

sie_uk

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I have a 3700x. At stock its 3.6ghz. High voltage = high temps. I undervolted from 1.45v to 1.3v on the cpu. This makes it the max voltage. I then overclocked the cpu to 4.2 ghz. It now runs at 38 degrees idle instead of 56. Max when bench marking is now 70 not 82. I do use an AIO cooler
 
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I have a 3700x. At stock its 3.6ghz. High voltage = high temps. I undervolted from 1.45v to 1.3v on the cpu. This makes it the max voltage. I then overclocked the cpu to 4.2 ghz. It now runs at 38 degrees idle instead of 56. Max when bench marking is now 70 not 82. I do use an AIO cooler
Thanks for your info. My temps are a little bet better now that I reset the water pump and install the latest bios for my mb. Idle when from about 56C to now 44C. Also I am now running AMD Ryzen Master to control everything. I only run it at Defaut setting, which I assume, is keeping the CPU at "stock",which is 3800 boost to 4700GHz. So according to this Master program at idle, temps about 44C, CPU clock speed about 100GHz & CPU Voltage about 0.458. Under bench marking, Max temps about 94.7C, Max CPU clock speed 3940GHz & Max CPU Voltage about 1.311. I feel a bit safer now that I don’t see any 107C temps, but I still would like to see that 4700GHz, which is what AMD says this 3900XT is suppose to do. Now I assume that the 94.7C temp is what is keeping the clock speed to not go over 3940GHz? Am I right? Also I did save a little money on my cooler by going with the Cooler Master, Masterliquid Lite 240. Do you think I really should go with a much more expensive cooler? Like what model cooler is yours? Or any other advice you might have would be appreciated.
 
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Hey, I took of the front cover to my computer case, all input & outputs plus power button are at on the top so the front cover is just for looks. So now the air flow is a lot better, my AIO cooler is at the front of my case. My idle temps came down to about 38C from 44C, I’m feeling better all the time now. Computer doesn’t look as nice, but I really don’t care that much about looks, more important that this thing last a long time. But I still have not seen over 3940MHz speed? And that is only running a test. In the real word, I use Pinnacle Studio 23 and when I render out to a 4 Ultra K video, most of them over 20Gbs , I still only see about 2100MHz speeds. So it takes almost 2.5 hrs to render a 20Gbs video. So I am really confused. If this thing won’t even run at the stock speed that AMD says it is suppose to run at, when it is working real hard at rendering, then OCing it is not going to see any faster speeds will it? My last computer was an intel i7-5820k CPU 6 core. It ran at 3,300MHz all the time and when pushed ran up to 3,800 MHz., So why does this AMD 3900XT 12 core has never ran over 3940MHz? AMD says it will run at 3,800MHz up to 4,700MHz. I’m getting a little flustered. Can any one explain things to me?
 

aussie7

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install cpu-z, this will show you the speed of your cpu and what the voltage is
I have my volts set to Auto in bios and my 3900XT gets upto around 86c while running prime95 under AIO cooler
auto volts and auto multiplier means they will fluctuate depending on the cpu load
I would consider 95c as the highest it should get upto
 

citay

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This thread a bit of a mess, isn't it...

Ok, you updated to the latest BIOS. If you go to "Save & Exit", there should be a point "Restore defaults". This is always a good place to start.

About the frequencies. Windows task manager is highly inaccurate, it averages over time. I don't know why people keep looking at that for CPU frequencies.
Use something like https://www.alcpu.com/CoreTemp/

A great tool is also HWinfo64: https://www.fosshub.com/HWiNFO.html
Under "sensors", you can see the maximum multiplier the CPU has hit, which corresponds to the frequency.



But the maximum turbo clocks are for single-core load. If you run a benchmark that loads all threads (or close to), you will never reach that high of a boost clock, naturally. The 3900XT should go up to about 4.3 GHz with multithreaded load. But it only reaches that if there is enough "thermal budget" remaining. If for some reason the cooling is not adequate and it gets too hot, it will not boost to those high frequencies. Also, it has a certain power limit (3900XT: 142W). So the turbo clocks are further limited by that. The more cores are fully loaded, the less high it can clock, to stay within the power limit. One publication tested around 4 GHz in the Blender benchmark, at 89°C with a Noctua NH-U14S (pretty good air cooler). This frequency is about the same as the normal 3900 non-XT. Why? Power limit. Only in more single-threaded tasks, the 3900XT is faster (by about 3%).

For the 3900, XT or non-XT, overclocking actually makes no sense. The Precision Boost 2 takes those CPUs right to their limit already. So if you were to tweak something, power consumption and heat output would rise dramatically, while not adding much performance. So it's a good idea that you wanted to lower the heat output somewhat, this CPU is getting quite hot as it is. But you have to know what you're doing. If you don't, stick to the defaults. But at least use better tools to observe the behaviour of the CPU 🙂
 

herbxfedxlio150702d9

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I think restoring defaults is a good place to start. If you could control air flow in your case you might just be having a flow issue. I am on a Ryzen 3600 running at 4.2Ghz all day and my temps don't go higher than 63. At idle I sit at 38. I control the fans in the bios and with NZXT CAM (when I'm feeling lazy)
 
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Well things are getting a lot better. Been tweaking the air flow inside my case, CPU clock speeds, and CPU voltage. Now the computer idles about 39C and when Studio is rendering long videos (like for more than an hour) I see max temps up to about 87C with CPU speeds at about 4300MHz. So I feel a lot more confidence in it not overheating. Still wish I would see a little more speed, sense 4700MHz is where it’s like stock. But, it is a bit faster than my last computer, and I feel safe about the temps now. So thanks a lot guys. I really appreciate your input.
 

Alan J T

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. Still wish I would see a little more speed, sense 4700MHz is where it’s like stock. B
That is for Single core only, more than one core it will drop to 4.0 to 4.4 Depending on load and temp. Most likely you are hitting the power limit.

As you can see I hit the power limit. Not sure if it can be increased or not.
CIN  HWM.jpg
 
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Hey, thanks for that info. I didn’t know that the 4700MHz was only for software that uses only one core. Now my video editing software is made to run on all the cores it can get. So I guess 4300MKz on most of the cores is really good. Now is that an AMD thing? My last computer was a Intel i7-5820k 6 core hyper thread and stock at 3300MKz to 3800MKz, but OC to 4200Mkz all the time. Even in my video program. At least that’s what the intel program told me that I used to OC with. Now I’m am a lot more satisfied now that temps stay under 87c even when rendering video for over an hr. at about 4300MKz. All ways looking for a quicker way to work though. For now I will leave things the way they are until I understand AMD better. Thanks a lot guys!
 

citay

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It makes no sense to overclock the 3900XT. AMD squeezes 99% out of it already with the Precision Boost 2, they went right to the limit of what this chip is capable of. For the 1% that's left, you'd have to apply too much voltage, which results in a LOT more energy consumption and thus heat production, while not achieving much in terms of performance. In fact, if it starts to throttle because the thermal budget is exhausted, you will LOSE performance compared to stock settings.

To quote https://www.guru3d.com/articles_pages/amd_ryzen_9_3900xt_review,27.html :
The new XT processors have been pushed to the max. Tweaking them while applying more voltage will increase heat levels rapidly. With LCS (280mm) we rapidly passed 85 Degrees C closing in at 90 Degrees C. We reached an all-core 4400 MHz and some might be able to hit 4500 MHz, however, the results are barely better. Leave the processor at defaults we'd say as AMD already did the maximum refining and tweaking for you.
Even PBO, AMD's own "modest" OC function, is not advisable on this CPU. It is right at the edge of usable efficiency already. Anything more, and the power consumption jumps up drastically, while the performance plus just isn't there.

If you want more speed, you might want to learn how to tune the RAM some more. On both the latest Intel and AMD CPUs, this makes way more sense than CPU OC.
 
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It makes no sense to overclock the 3900XT. AMD squeezes 99% out of it already with the Precision Boost 2, they went right to the limit of what this chip is capable of. For the 1% that's left, you'd have to apply too much voltage, which results in a LOT more energy consumption and thus heat production, while not achieving much in terms of performance. In fact, if it starts to throttle because the thermal budget is exhausted, you will LOSE performance compared to stock settings.

To quote https://www.guru3d.com/articles_pages/amd_ryzen_9_3900xt_review,27.html :


Even PBO, AMD's own "modest" OC function, is not advisable on this CPU. It is right at the edge of usable efficiency already. Anything more, and the power consumption jumps up drastically, while the performance plus just isn't there.

If you want more speed, you might want to learn how to tune the RAM some more. On both the latest Intel and AMD CPUs, this makes way more sense than CPU OC.
Thanks, citay, I’ve never OC the ram before, so I’ll have to do some research before I fell comparable to do that. So I will check into that, thanks. There is one thing I don’t understand. Maybe you can help me understand it. When I run this CPU at all default settings and rendering video, over an hour at a time, I never see more than 3940MKz speeds, with temps not over 83c, but when I OC (with Ryzen Master) setting to 4400MKz,. Then I see about 4300MKz in most of the cores and temps not over 87c which gives me about 20 to 25% quicker times. So my question is why don’t I see any faster speeds at default settings? Also, do you think if I keep the OC settings at 4400MKz, will my computer last a long time? Which is my main concern. Thanks for your input.
 
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citay

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It depends on where you check the CPU frequency. BTW, in MHz, not MKz. After Heinrich Hertz.
Anyways. The task manager is completely unusable for checking that. You have to check that with something like Core Temp: https://www.alcpu.com/CoreTemp/

Here are boost clock statistics of the 3900XT with certain loads, going from single-threaded to fully multithreaded load:



I don't know what they used, but certainly not the task manager, that's for sure.

Bonus: Core Temp also shows the "Power" value, which is what the CPU reports as its power consumption. Observe that value with the standard settings and with OC settings. You will see that with OC, the power draw will most likely increase rather drastically. But if you were to measure the performance difference, it would often be only single-digit.

What is the outcome of only a slight performance increase, but a big increase in power draw? Way worse efficiency. Why? Because way more energy is spent for just a slightly shorter duration of time it takes to finish a certain processing task.

With the 3900XT, as well as for example with an Intel 10900K, both manufacturers went right to the limit of efficiency by default. For each single (!) percent of performance improvement over stock, you basically have to take a 10-20% increase in power consumption. This is almost unheard of in previous CPU generations. Well, the 9900K was already pretty adventurous by default, but these new top CPUs take the cake, there really isn't much more in them, unless you want to incur serious penalties in power draw.

Look at this graph of the 3700XT for example:



Don't mind that's it's a different CPU model and a different topic (namely, how a lower PPT limit can quickly improve efficiency, i.e. power draw decreasing much more than performance does, and undervolting with an offset isn't nearly as effective).

But we can also draw conclusions about overclocking from this type of graph. Just observe towards the top right, how the curve will rise ever more steeply. This means that, after a certain point, for ever smaller performance increases, the power consumption rises a lot more.

This is basically the CPU telling you that it is at the limit of its optimal efficiency range. In the past, these curves were a lot flatter initially, especially with Intel CPUs, cause they took it easy when determining the CPU frequencies. Intel had no reason to go to the limit, because they dominated AMD and had no real competition at the high end. So they left a lot "in the tank" and focused more on efficiency by default. This was the day when CPUs still had a sizeable OC headroom. These days are over. AMD has become a dangerous competitor, they have all but perfected their boost modes, and now both manufacturers go right to the limit with their high-end CPUs.

If these curves were plotted further, at some point they would go up horizontally, meaning no additional VCore can get this CPU to perform any better without becoming unstable or throttling itself. What i'm saying with all this is, if you notice power consumption jumping up considerably for a minor OC, this is the CPU shouting "enough".

And any OC cancels out the fully intelligent power management and the granular turbo modes. The CPU at stock, without PBO and without manual OC, is already slightly above the most efficient range. PBO with a slight +200 MHz will finally push it over it, and manual OC can quickly make the CPU massively inefficient.
 
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