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GMP damaging Zen 5 CPUs?

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Re: GMP damaging Zen 5 CPUs?

#121

Post by userbinator »

spoaceman7777 wrote: post #101
topspin wrote: post #4

As there is ongoing drama with Zen 5 and power issues, there are people with the instruments and the motivation to investigate this. You should consider contacting Gamers Nexus, and help them to get your test suite running. They can measure power draw and do a thermal analysis of this CPU, and they'd likely be eager to do it, given the possibility of making a bunch of dramatic YouTube content about design flaws in wi…

All you really need to see is the picture of the CPU with thermal paste only on one half. Thermal throttling is tuned to work when there is 1. a sufficient heatsink (theirs was significantly below requirements) and 2. it is installed correctly so that its triggers for downclocking happen with the correct timing. This is just another instance of ridiculous PEBCAK error

I'm not as sure about AMD CPUs (and they were known for having far worse overheat behaviour back in the early 2000s) but there are plenty of stories of Intel CPUs working for many years, sitting at the thermal limits, with the (stock) heatsink not even in contact, thanks to their cheap push-pin retention mechanism.

Re: GMP damaging Zen 5 CPUs?

#122

Post by mrheosuper »

themafia wrote: post #78
MrGilbert wrote: post #43

Earlier quoted context omitted.

> [...] a bunch of dramatic YouTube content [...] That framing doesn't do him and the team justice. There is (or better, was) a 3.5h long story about NVIDIA GPUs finding their ways illegaly from the US to China, which got taken down by a malicious DMCA claim from Bloomberg. It is quite interesting to watch (Can be found archive.org). GN is one of the last pro-consumer outlets, that keep on digging and shaking the tre…

> which got taken down Not everywhere: https://archive.org/details/the-nvidia-ai-gpu-black-market-i...

When something is uploaded to the internet, it won't be easy to take it down.

Ask Beyonce.

Re: GMP damaging Zen 5 CPUs?

#123

Post by userbinator »

mk_stjames wrote: post #28
tux3 wrote: post #7

The room temperature or precise way the paste was applied should not matter. Modern CPUs have very advanced dynamic voltage and frequency scaling (DVFS), which accounts for several sensors, including temperature. These big x86 CPUs in stock configuration can throttle down to speeds where they can function with entirely passive cooling, so even if the cooler was improperly mounted, they'd only throttle. All that to sa…

This was my first question as well- I thought it had been a long, long time since you could fry a CPU by taking away the heatsink. As in... what, AMD K6 / early Pentium 4 days was the last time I remember hearing about cpu cooler failing and frying a cpu?

This infamous video: https://www.youtube.com/watch?v=06MYYB9bl70

Re: GMP damaging Zen 5 CPUs?

#124

Post by ndiddy »

spoaceman7777 wrote: post #101
topspin wrote: post #4

As there is ongoing drama with Zen 5 and power issues, there are people with the instruments and the motivation to investigate this. You should consider contacting Gamers Nexus, and help them to get your test suite running. They can measure power draw and do a thermal analysis of this CPU, and they'd likely be eager to do it, given the possibility of making a bunch of dramatic YouTube content about design flaws in wi…

All you really need to see is the picture of the CPU with thermal paste only on one half. Thermal throttling is tuned to work when there is 1. a sufficient heatsink (theirs was significantly below requirements) and 2. it is installed correctly so that its triggers for downclocking happen with the correct timing. This is just another instance of ridiculous PEBCAK error

This is per design. On AM5 processors, there's a hotspot on the lower half of the processor where the dies that contain the CPU cores are located. Noctua recommends that AM5 users mount their coolers shifted towards the lower side of the processor for optimal cooling performance, see https://noctua.at/en/offset-am5-mounting-technical-backgroun... . You may have missed the paragraph in the article that explicitly points this out:

> We use a Noctua cooling solution for both systems. For the 1st system, we mounted the heat sink centred. For the 2nd system, we followed Noctua's advice of mounting things offset towards what they claim to be the hotter side of the CPU. Below is a picture of the 2nd system without the heat sink which shows that offset. Note the brackets and their pins, those pins are where the heat sink's pressure gets centred. Also note how the thermal paste has been squeezed away from that part, but is quite thick towards the left.

Re: GMP damaging Zen 5 CPUs?

#125

Post by RachelF »

tux3 wrote: post #7

The room temperature or precise way the paste was applied should not matter. Modern CPUs have very advanced dynamic voltage and frequency scaling (DVFS), which accounts for several sensors, including temperature. These big x86 CPUs in stock configuration can throttle down to speeds where they can function with entirely passive cooling, so even if the cooler was improperly mounted, they'd only throttle. All that to sa…

Yes, this is the point - software should never be able to physically damage the hardware it is on.

If it can, then the hardware is to blame.

Re: GMP damaging Zen 5 CPUs?

#126

Post by userbinator »

bob1029 wrote: post #9

Could be the power supply and load profile? I've heard some really wild noises coming out of my zen4 machine when I've had all cores loaded up with what is best described as "choppy" workloads where we are repeatedly doing something like a parallel.foreach into a single threaded hot path of equal or less duration as fast as possible. I've never had the machine survive this kind of workload for more than 48 hours with…

I've never had the machine survive this kind of workload for more than 48 hours without some kind of BSOD.

Then you shouldn't trust the results of your work either, as that's indicative of a CPU that's producing incorrect results. I suggest lowering the frequency or even undervolting if necessary until you get a stable system.

...and yes, wildly fluctuating power consumption is even more challenging than steady-state high power, since the VRMs have to react precisely and not overshoot or undershoot, or even worse, hit a resonance point. LINPACK, one of the most demanding stress tests and benchmarks, is known for causing crashes on unstable systems not when it starts each round, but when it stops.

Re: GMP damaging Zen 5 CPUs?

#127

Post by userbinator »

thway15269037 wrote: post #109

I don't know about GMP, but I recently built a PC with 9950X3D. As part of initial testing, I ran Prime95 for 48 hours. Everything ran stable, but I noticed that part of the tests, I think it was FFT or something like that, caused incredibly sharp increase in temp. We are talking 60C average in the rest of the test vs immediate (less than a 5 seconds) 95+ degrees when that FFT thingie started. It was very weird. That…

Try LINPACK, it's even more stressful than Prime95.

Re: GMP damaging Zen 5 CPUs?

#128

Post by RachelF »

topspin wrote: post #4

As there is ongoing drama with Zen 5 and power issues, there are people with the instruments and the motivation to investigate this. You should consider contacting Gamers Nexus, and help them to get your test suite running. They can measure power draw and do a thermal analysis of this CPU, and they'd likely be eager to do it, given the possibility of making a bunch of dramatic YouTube content about design flaws in wi…

AMD has failed to be reliable with its Zen 4 and Zen 5 consumer CPUs, just at the same time Intel did the same with their 13k and 14k higher end CPUs.

AMD is somewhat worse than Intel as their DDR5 memory bus is very "twitchy" making it hard to get the highest DDR5 timings, especially with multiple DIMMs per channel.

Re: GMP damaging Zen 5 CPUs?

#129

Post by protocolture »

I have a Ryzen and it ran fine until one day, after some load, it wont run at all with the virtualisation options turned on anymore.

Having read all I can on the issue its largely been ignored by AMD.

If its some kind of thermal runaway issue that would not surprise me.

Re: GMP damaging Zen 5 CPUs?

#130

Post by dcrazy »

mrb wrote: post #92
db48x wrote: post #19

> The so-called TDP of the Ryzen 9950X is 170W. The used heat sinks are specified to dissipate 165W, so that seems tight. TDP numbers are completely made up. They don’t correspond to watts of heat, or of anything at all! They’re just a marketing number. You can't use them to choose the right cooling system at all. https://gamersnexus.net/guides/3525-amd-ryzen-tdp-explained-...

You are correct. In fact these guys measured a maximum socket power consumption of 240 watt using a 9950X at stock settings, running prime95. So far above the "170 watt" TDP: https://hwbusters.com/cpu/amd-ryzen-9-9950x-cpu-review-perfo...

I don’t understand this argument. If the CPU dissipated an equal number of watts of heat energy as it consumed from the wall, there wouldn’t be any energy left to do actual useful work. Isn’t the extra 100W accounted for by things like changing the state of flip-flops? In other words, mustn’t one consider the entropy reduction of the system as an energy sink?
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