Question What's best for checking 3900x stability?

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zx128k

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I'm sure some encoding loads can hit it hard... but try that P95 custom setup with AVX boxes ticked and see if it's not hitting your CPU hard. And the thing is, it's consistently and unrelentingly hard, never slacking off as scenes change or the end of an encoding comes up and it loops. It's just unrealistic which why I feel it's good only for derating for processing stability.

The other one is probably better for heat output though; with larger FFT's and no AVX I think it's consistently putting more of the CPU in use and that ticks up the heat output somewhat.
Basically being stable is regardless of the load. If you overheat in any of the Prime95 you are not stable.

You can stress test in lighter SSE loads but you can't state you are stable.
 
Basically being stable is regardless of the load. If you overheat in any of the Prime95 you are not stable....
Overheating alone? If the processor stays operating? I take 'stable' to mean it's still alive and ticking with valid results, even if boiling water to make tea with your CPU. Not a desirable way to operate...but if it's stable, it's stable.

What OP's trying to do really is not clear to me. He's absolutely killing performance of his 3900k, but that's OK if what's desired is reliable operation, unattended, in extreme conditions. Just don't compare it's processing performance to other systems except to find out how much he's giving up to obtain said extreme reliability and durability. And don't be so confident it's really resulting a longer life since fixing a clock and voltage, however low, never lets it enter the C6 'deep sleep' states that it could if left to it's own protection mechanisms.
 
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zx128k

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Overheating alone? If the processor stays operating? I take 'stable' to mean it's still alive and ticking with valid results, even if boiling water to make tea with your CPU. Not a desirable way to operate...but if it's stable, it's stable.

What OP's trying to do really is not clear to me. He's absolutely killing performance of his 3900k, but that's OK if what's desired is reliable operation, unattended, in extreme conditions. Just don't compare it's processing performance to other systems except to find out how much he's giving up to obtain said extreme reliability and durability. And don't be so confident it's really resulting a longer life since fixing a clock and voltage, however low, never lets it enter the C6 'deep sleep' states that it could if left to it's own protection mechanisms.
If you are overheating that is not a normal operation. The cpu will reduce clock speeds and thus performance. The higher operation temperatures increase leakage currents and affect lifespan of the cpu. I love how you have created a straw man that somehow stock reliability is an extreme reliability. Then you are just stating if it operates and I notice no problems then it must be okay. Enjoy your data loss, micro stuttering in games, hitching and odd bugs. This forum is full of problems created by people who don't have stable builds.

There are several factors contributing to the CPU power consumption; they include dynamic power consumption, short-circuit power consumption, and power loss due to transistor leakage currents.

The dynamic power consumption originates from the activity of logic gates inside a CPU. When the logic gates toggle, energy is flowing as the capacitors inside them are charged and discharged. The dynamic power consumed by a CPU is approximately proportional to the CPU frequency, and to the square of the CPU voltage.

So if you increase voltage and frequency you increase the power consumption of the cpu. This increases cooling and reduces stability. You increase voltage to help stability but you now must cool the higher power consumption so that the cpu's temperatures are low enough that you maintain the lifetime of the part.

Power consumption due to leakage power emanates at a micro-level in transistors. Small amounts of currents are always flowing between the differently doped parts of the transistor. The magnitude of these currents depend on the state of the transistor, its dimensions, physical properties and sometimes temperature. The total amount of leakage currents tends to inflate for increasing temperature and decreasing transistor sizes.

Sensitive electronics like CPUs have a finite lifespan and running them at higher temperatures shortens it. This is why Ryzen cpu's can lower voltage and increase frequency at lower temperatures. This is also why lifespan is affected if you do the opposite.

So go for high temperatures, a higher constant voltage and frequency. It's not my cpu, why would I care. Find out 6 months later after running heavy video encoding loads that your cpu hit 90c for long periods and now is no longer even stable to run games.
 

zx128k

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The CPU High Temperature Clock Limit on my 3800x is 4300MHz >= 80c. "High Temperature Clock Limit" determines the maximum allowed clock when the temperature exceeds the threshold.

I only hit 80c with a 4.4GHz all core overclock.

For a 4.3GHz all core overclock I don't hit 75c even in Prime95 8kfft or even the hotter aida64 cpu FPU.

So 4.3GHz is safe and 4.4GHz looks like a small risk.

Now there are reports that the CPU High Temperature Clock Limit on my 3800x is changed to 4300MHz >= 75c. source

Once you set the frequency above the CPU High Temperature Clock Limit you need to cool that cpu. The cpu won't reduce the clock speed at high temps.

This is why,

3800XNot Tested4.20GHz1.275V100%
3800XNot Tested4.25GHz1.287VTop 53%
3800XNot Tested4.30GHz1.300VTop 20%
3900XNot Tested4.00GHz1.200V100%
3900XNot Tested4.05GHz1.212VTop 87%
3900XNot Tested4.10GHz1.225VTop 68%
3900XNot Tested4.15GHz1.237VTop 35%
3900XNot Tested4.20GHz1.250VTop 6%
https://siliconlottery.com/pages/statistics
 
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zx128k

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I'm pretty much ignoring what you wrote as it's largely pedantic.

I'm trying to understand why someone buys a $500 processor and turns it's performance into that of a $300 processor. It makes no sense unless looking for extreme reliability, which is logically valid in certain circumstances.
People are reporting degrading @ 1.325volts and less, I am keeping my cpu at stock atm. You may need to find the CPU's FIT voltage before you overclock. The high temps and a voltage above FIT could be causing degradation. I am trying to work out my FIT at the moment.

I am following, "If you want to be able to find this voltage turn on PBO and max PPT, TDC and EDC and run a worse-case workload as of The Stilts recommendation."

3700x degraded.
Hey guys, I just degraded my 3700x that I have been running with since launch. I had my settings at 4.4ghz 1.32V and 3800 14-15-12 1.6V. Would it have been the memory voltage or core voltage that degraded it? The chip seems alright when stock and I don't really mind the degradation, I just want to know what caused it.
https://www.reddit.com/r/overclocking/comments/eml9i4 View: https://www.reddit.com/r/overclocking/comments/eml9i4/3700x_degraded/


R5 3600 degraded.

OC Report - CPU
Hi guys. I recently found out my 4.125ghz overclock on my 3600 is no longer stable after I ran cinebench R15 to test the performance of the new bios version. At first I thought the bios was at fault but it turns out that even rolling back had the chip still unstable when at the previously stable 4.125ghz 1.32V overclock. I ran this OC for 4 months and I have now lost 75mhz on the chip meaning my previously stable 4.125ghz OC is now a 4.05ghz OC.
https://www.reddit.com/r/overclocking/comments/ej8uqa View: https://www.reddit.com/r/overclocking/comments/ej8uqa/r5_3600_degraded/


"So i ran 1.287v 4.125ghz with load temps ~85C for roughly 2 months(?) and it started out as being stable. I then took a break from overclocking for probably around a month and when i tried overclocking for a school project, 4.1ghz 1.287v didn't even run cinebench and 4.05ghz 1.287v isn't stable after like 20 minutes. My chips FIT gives a voltage of 1.262V under prime95 small fft at 60C." - u/xphoenixd
'I am still shocked people recommend this voltage. I only just realized my chip degraded early today and I am honestly really pissed that people say 1.325V is safe when they have no clue them self about the maximum FIT voltage. My chip ran 4.125ghz 1.32V for 4 months only to see it be completely unstable after these 4 months. Under load the temperatures reached 65C in Prime95 AVX so it defiantly was not a temperature issue. My chips max FIT voltage is 1.306V, that is what I get in Prime95 small FFT avx. Please never tell anyone to run 1.325V into a zen 2 chip again. You can do it yourself at your own risk, just don't tell others to. This is my post on it https://www.reddit.com/r/overclocking/comments/ej8uqa View: https://www.reddit.com/r/overclocking/comments/ej8uqa/r5_3600_degraded/
.' - u/hydromos
'I knew 1.325V wasn't safe. My chips FIT maximum voltage is ~1.3V and I ran 1.325V since I got my 3600x. I honestly was expecting to see degradation and degradation I saw after 4 months of use. The system was used for 3d animation in blender by my wife so it saw a pretty hard life. I forgot to mention temps, they were around 70C since the chip had a NH-D15 on it.' - u/reocuros
So yeah, 1.325V is not safe. The maximum safe voltage for your personal zen 2 cpu is... I have no clue. If you want to be able to find this voltage turn on PBO and max PPT, TDC and EDC and run a worse-case workload as of The Stilts recommendation.

Also do not push past the Fmax on your cpu while at maximum FIT voltage. It can actually make the situation your cpu is in dangerous and add a risk of degradation.

If you have any questions feel free to ask :)

TL:DR Pushing past your chips maximum FIT voltage is not safe and will cause accelerated degradation.
source

More evidence.
Quote: Originally Posted by VPII"Hi @The Stilt, if I may ask seen that I only overclock manually. Would you say that 1.28vcore would be safe. Power draw during IBT with Linpack maxes out at 198watt and temps around 78 to 79C max. I have the option of running it at 4.29Ghz about 25mhz less but only using 1.25vcore." - VPII"Probably, but ultimately it depends on the silicon characteristics.You can check how high voltage FIT allows by increasing PPT, TDC and EDC to the maximum and running a worst-case workload. " - The Stilt
 
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zx128k

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Oh fiddlesticks...
That makes those chips rather fragile compared to Intel's doesn't it?

All the more reason not to overclock Ryzen 3000...
My FIT is 1.306-1.344 volts vcore. at approx. 71c with aida64 cpu FPU. Yeah and it appears that each chip is different. So you have to find your personal chips safe FIT.

To find my FIT I set PBO on and the power limits to motherboard. I set scalar to 1x. Opened HWiNFO with aida64 open and got the above range. So I would low ball the value and say 1.306 volts vcore is my FIT. Maybe prime95 is better 8k FFT is see now low the voltage goes.

So my cpu seems to be the same as,

"around 1.325V" - The Stilt
So basically this means the maximum FIT voltage is around 1.325V (not 1.325V, around 1.325V) under high current scenarios but this maximum FIT voltage, depends on the silicon characteristics. Meaning chips with different silicon characteristics will have different voltage tolerance meaning one voltage can not be the maximum safe voltage for all chips.
https://www.reddit.com/r/Amd/comments/ejgc6p View: https://www.reddit.com/r/Amd/comments/ejgc6p/1325v_is_not_safe_for_zen_2/
 

zx128k

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So TL:DR Pushing past your chips maximum FIT voltage is not safe and will cause accelerated degradation.

and...

Also do not push past the Fmax on your cpu while at maximum FIT voltage.

Fmax is set by the cpu PB and increased by PBO. So if you are at FIT or above, have high temps and are higher than FMax. Then your cpu could degrade. The fused Fmax for the 3900x is 4650MHz and for the 3800x the fused fmax is 4550Mhz. So you can never have a Fmax higher than the fused values.

Source https://www.vortez.net/articles_pages/amd_ryzen_9_3900x_review,4.html

Better cooling means spending longer at Fmax under Precision Boost (the maximum frequency defined by your PB settings). PBO meanwhile will increase Fmax (which can now also be tweaked in software) while preserving the PB curve (i.e. the lower Fmax offests for when 2, 3, 4 etc. cores are active).
On reddit posts state the following.

"For x% over fmax, voltage must be lowered by x% of the maximum FIT voltage, in theory anyways, that may not be safe in actuality. Though I would doubt it not being safe." - MadLad81#9445 (discord tag)


View: https://www.reddit.com/r/overclocking/comments/ejd5c9/1325v_is_not_safe_for_zen_2/fcxrk78/

If you push over Fmax you are going over the rated spec meaning your current draw will be higher then spec. Let's just say at 4.2ghz 1.3V you are pulling 100A. In this situation you are on the FIT maximum voltage and on the Fmax so you are within spec.
If you then raise the clocks to 4.242ghz at the same 1.3V your current will be ~101A. Due to close to linear current increase when frequency is raised. (4.242/4.2 * 100 = 101)
Now if you lower your voltage by the same amount you raised your frequency (1%) your current will be back in safe limits. This works because voltage raises or lowers current by the same amount that is was changed. (101 / (1.3/1.287) = 99.99)
This formula isn't perfect but works pretty well.
 
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