I am giving up on Intel and have bought an AMD Ryzen 9950X3D

I don't think 64GB ECC UDIMM is commercially available yet. I use Geizhals to check for EU availability: https://geizhals.eu/?cat=ramddr3&xf=7500_DDR5~7501_DIMM~7761...

In my experience, it's generally unwise to push the platform you're on to the outermost of its spec'd limits. At work, we bought several 5950X-based Zen3 workstations with 128GB of 3200MT/s ECC UDIMM, and two of these boxes will only ever POST when you manually downclock memory to 3000MT/s. Past a certain point, it's silicon lottery deciding if you can make reality live up to the datasheets' promises.

Yeah, with that kind of markup you might as well just buy new ones IF they break, or just spend the extra budget on better quality parts. Just having to pick a very specific motherboard that probably is very much not optimal for your build will blow the costs up even more, and for what gain?

I've been building my own gaming and productivity rigs for 20 years and I don't think memory has ever been a problem. Maybe survivorship bias, but surely even budget parts aren't THIS bad.

If you're on Linux, dmesg containing

  EDAC MC0: Giving out device to module amd64_edac

See my blog post about it (it was top of HN): https://sunshowers.io/posts/am5-ryzen-7000-ecc-ram/

This is weird. I have used many ASUS MBs specified as "can run ECC and non-ECC" and this has always meant that there was an ECC enabling option in the BIOS settings, and then if the OS had an appropriate EDAC driver for the installed CPU ECC worked fine.

I am writing this message on such an ASUS MB with a Ryzen CPU and working ECC memory. You must check that you actually have a recent enough OS to know your Threadripper CPU and that you have installed any software package required for this (e.g. on Linux "edac-utils" or something with a similar name).

Usually, if a vendor's spec sheet for a (SOHO/consumer-grade) motherboard mentions ECC-UDIMM explicitly in its memory compatibility section, and (but this is a more recent development afaict) DOES NOT specify something like "operating in non-ECC mode only" at the same time, then you will have proper ECC (and therefore EDAC and RAS) support in Linux, if the kernel version you have can already deal with ECC on your platform in general.

I would assume your particular motherboard to operate with proper SECDED+-level ECC if you have capable, compatible DIMM, enable ECC mode in the firmware, and boot an OS kernel that can make sense of it all.

Whether you will see ECC errors depends a lot on how much memory you have and how old it is.

A computer with 64 GB of memory is 4 times more likely to encounter memory errors than one with 16 GB of memory.

When DIMMs are new, at the usual amounts of memory for desktops, you will see at most a few errors per year, sometimes only an error after a few years. With old DIMMs, some of them will start to have frequent errors (such modules presumably had a borderline bad fabrication quality and now have become worn out, e.g. due to increased leakage leading to storing a lower amount of charge on the memory cell capacitors).

For such bad DIMMs, the frequency of errors will increase, and it may become of several errors per day, or even per hour.

For me, a very important advantage of ECC has been the ability to detect such bad memory modules (in computers that have been used for 5 years or more) and replace them before corrupting any precious data.

I also had a case with a HP laptop with ECC, where memory errors had become frequent after being stored for a long time (more than a year) in a rather humid place, which might have caused some oxidation of the SODIMM socket contacts, because removing the SODIMMs, scrubbing the sockets and reinserting the SODIMMs made disappear the errors.

I had a somewhat dodgy stick of used RAM (DDR4 UDIMM) in a Supermicro X11 board. This board is running my NAS, all ZFS, so RAM corruption can equal data corruption. The OS alerted me to recoverable errors on DIMM B2. Swapped it and another DIMM, rebooted, saw DIMM error on slot B1. Swapped it for a spare stick. No more errors.

This was running at like, 1866 or something. It's a pretty barebones 8th gen i3 with a beefier chipset, but ECC still came in clutch. I won't buy hardware for server purposes without it.

I see a particular ECC error at least weekly on my home desktop system, because one of my DIMMs doesn't like the (out of spec) clock rate that I make it operate at. Looks like this:

    94 2025-08-26 01:49:40 +0200 error: Corrected error, no action required., CPU 2, bank Unified Memory Controller (bank=18), mcg mcgstatus=0, mci CECC, memory_channel=1,csrow=0, mcgcap=0x0000011c, status=0x9c2040000000011b, addr=0x36e701dc0, misc=0xd01a000101000000, walltime=0x68aea758, cpuid=0x00a50f00, bank=0x00000012
    95 2025-09-01 09:41:50 +0200 error: Corrected error, no action required., CPU 2, bank Unified Memory Controller (bank=18), mcg mcgstatus=0, mci CECC, memory_channel=1,csrow=0, mcgcap=0x0000011c, status=0x9c2040000000011b, addr=0x36e701dc0, misc=0xd01a000101000000, walltime=0x68b80667, cpuid=0x00a50f00, bank=0x00000012

It's always the same address, and always a Corrected Error (obviously, otherwise my kernel would panic). However, operating my system's memory at this clock and latency boosts x265 encoding performance (just one of the benchmarks I picked when trying to figure out how to handle this particular tradeoff) by about 12%. That is an improvement I am willing to stomach the extra risk of effectively overclocking the memory module beyond its comformt zone for, given that I can fully mitigate it by virtue of properly working ECC.

I pick up old serves for my garage system. With edac it is a dream to isolate the fault and be instantly aware. It also lets you determine the severity of the issue. Dimms can run for years with just the one error or overnight explode into streams of corrections. I keep spares so it’s fairly easy to isolate any faults. It’s just how do you want to spend your time?

You have to go pretty far down the rabbit hole to make sure you’ve actually got ECC with [LP]DDR5

Some vendors use hamming codes with “holes” in them, and you need the CPU to also run ECC (or at least error detection) between ram and the cache hierarchy.

Those things are optional in the spec, because we can’t have nice things.

I run a handful of servers and I have a couple that pop ECC errors every year or three, so YMMV.

I saw a corrected memory error logged every few hours when my current machine was new. It seems to have gone away now, so either some burn-in effect, or ECC accidentally got switched off and all my data is now corrupted. Threadripper 7000 series, 4x64GB DDR5.

Edit: it's probably because I switched it to "energy efficiency mode" instead of "performance mode" because it would occasionally lock up in performance mode. Presumably with the same root cause.

The difference between the "unbuffered" ECC DIMMs (ECC UDIMMs), which you must use in desktop motherboards (and in some of those advertised as "workstation" MBs) and the "registered" ECC DIMMs (ECC RDIMMs), which you must use in server motherboards (and in some of the "workstation" MBs), has existed for decades.

However in the past there have existed very few CPU models and MBs that supported either kind of DIMMs, while today this has become completely impossible, as the mechanical and electrical differences between them have increased.

In any case, today, like also 20 years ago, when searching for ECC DIMMs you must always search only the correct type, e.g. unbuffered ECC DIMMs for desktop CPUs.

In general, registered ECC DIMMs are easier to find, because wherever "server memory" is advertised, that is what is meant. For desktop ECC memory, you must be careful to see both "ECC" and "unbuffered" mentioned in the module description.

Seconding this. I'm looking for a fanless industrial mini PC with out of band ECC and I'm having a hell of a time.

> At least DDR5 has some level of ECC.

That is mostly to assist manufacturers in selling marginal chips with a few bad bits scattered around. It's really a step backwards in reliability.

I wish AMD wouldn't gate APU ECC support behind unobtainium "PRO" SKUs they only give out, seemingly, to your typical "business" OEMs and the rare Chinese miniPC company.

Excellent point. A single case fan is highly atypical and concerning.

I also have a fractal define case with anti noise padding material and dust filters, but my temperatures are great and the computer is almost inaudible even when compiling code for hours with -j $(nproc). And my fans and cooler are much cheaper than his.

I always wonder: how many sensors are registering that temp?

Because CPUs can get much hotter in specific spots at specific pins no? Just because you're reading 100, doesn't mean there aren't spots that are way hotter.

My understanding is that modern Intel CPUs have a temp sensor per core + one at package level, but which one is being reported?

Yes, I have read the article and I agree Intel should be shamed (and even sued) for inaccurate statements. But it doesn't change the fact it has never been a good idea to run desktop processors at their throttling temperature -- it's not good for performance, it's not good for longevity and stability, and it's also terrible for efficiency (performance per watt).

Anyway, OP's cooler should be able to cool down 250W CPUs below 100C. He must have done something wrong for this to not happen. That's my point -- the motherboard likely overclocked the CPU and he failed to properly cool it down or set a power limit (PL1/PL2). He could have easily avoided all this trouble.

> I think a lot of it boils down to load profile and power delivery

You said the right words but with the wrong meaning! On Gigabyte mobo you want to increase the "CPU Vcore Loadline Calibration" and the "PWM Phase Control" settings, [see screenshot here](https://forum.level1techs.com/t/ddr4-ram-load-line-calibrati...).

When I first got my Ryzen 3900X cpu and X570 mobo in 2019, I had many issues for a long time (freezes at idle, not waking from sleep, bios loops, etc). Eventually I found that bumping up those settings to ~High (maybe even Extreme) was what was required, and things worked for 2 years or so until I got a 5950X on clearance last year.

I slotted that in to the same mobo and it worked fine, but when I was looking at HWMon etc, I noticed some strange things with the power/voltage. After some mucking about and theorising with ChatGPT (it's way quicker than googling for uncommon problems), it became apparent that the ~High LLC/power settings I was still using were no good. ChatGPT explained that my 3900X was probably a bit "crude" in relative quality, and so it needed the "stronger" power settings to keep itself in order. Then when I've swapped to 5950X, it happens to be more "refined" and thus doesn't need to be "manhandled" — and in fact, didn't like being manhandled at all!

I wonder if cooling/power is really the key here. I've got a 5950x that ended up getting the water loop I'd intended for my next threadripper - only to find they were not selling the blasted things to anyone but a few companies. With the cooling sized for almost twice what the 5950x could put out, it has been a very stable machine for some crazy workloads. That old dog will likely keep the setup when a zen 5 TR gets swapped in.

For a long time, my Achille's heel was my Bride's vacuum. Her Dyson pulled enough amps that the UPS would start singing and trigger the auto shutdown sequence for the half rack. Took way too long to figure out as I was usually not around when she did it.

If you have a double conversion UPS that is complaining about less than 100W deviation, I would recommend you check the UPS for a component that is out of spec or on the way to failure.

I'm sure there are spec's for how fast a PS should be able to ramp up in response to spikes in demand, how a motherboard should handle sudden load changes, etc.

But if your UPS (or just the electrical outlet you're plugged into) can't cope - dunno if I'd describe that as cratering your CPU.

Have you tried using powerprofilesctl to change the power profile to 'performance' instead of 'balanced' or 'power saver'? I think this would prevent the lowest idle states at least. Just a guesss, never had this problem myself.

My modern CPU problems are DDR5 and the pre-boot timing thing never completing. So a build of a 9700x that I did that WAS supposed to be located remotely from me has to sit in my office and have its hand held thru every reboot cuz you never know quite know when its doing to decide it needs to retime and randomly never come back. Requires pulling the plug from the back and waiting a few minutes then powering back, then waiting 30 minutes for 64gb of ddr5 to do its timing thing.

Crash on idle, interesting. Must be some timing issue related to down clocking, or maybe a voltage issue related to shutting off a core.

You could try using powerprofilesctl to change the mode from 'balanced' or 'power saver' to 'performance' since i think this may prevent the cpu from ever entering the throttled down low idle states that your freezing happens in. they are controlled with powerprofilesctl. You may also be able to add some flugs to grub config file. assuming you are using linux i guess.

If you are on Linux, there are long time known problems with low power cpu states. These states can be entered by your CPU when under low/no load.

A common approach is to go into the BIOS/UEFI settings and check that c6 is disabled. To verify and/or temporarily turn c6 off, see https://github.com/r4m0n/ZenStates-Linux

Just buy an AMD CPU. One person’s experience isn’t the world. Nobody in my circle has had an issue with any chip from AMD in recent time (10 years).

Intel is just bad at the moment and not even worth touching.

I wouldn't be so hopeless. Intel and AMD CPUs are used in millions of builds and most of them just work.

It's either bad luck, bad power quality from the mains, or something in the air in that particular area. I know plenty of people running AM5 builds, have done so myself for the last couple of years, and there were no problems with any of them apart from the usual amdgpu bugs in latest kernels (which are "normal" since I'm running mainline kernels — it's easy to solve by just sticking to lts, and it has seemingly improved anyway since 6.15).

> I thought of AMD Ryzen 7 5700

Definetly not that one if you plan to pair with a dedicated GPU! The 5700X has twice the L3 cache. All Ryzen 5000 with a GPU have only 16MB, 5700 has the GPU deactivated.

3 of my last 4 machines have been AMD x NVDA and I have been very happy. The intel x NVDA machine has been my least stable one.

Dell has been very loyal to Intel all these years, but i guess that is under pressure as well. As more and more customers look for AMD CPUs nowadays. I guess the CPU doesn't matter much in standard office company laptops and price is more important.

I'm not sure whether a "Dell Pro 16 Plus" is considered a "business laptop" (although I think so), but I'm using one right now and it has an AMD Ryzen AI 5 Pro CPU inside.

That ASUS motherboard is far from the cheapest available. If using it makes the user liable for failure, a large part of the market is unsuitable.

For both the cooler and the motherboard, AMD have too much control to look the other way. The chip can measure its own temperature and the conceit of undermining partners by moving things on chip and controlling more of the ecosystem is that things perform better. They should at least perform.

Thermal throttling originated as a safety feature. The early implementations were basically a "thermal fuse" in function, and cut all power to the system to prevent catastrophic hardware damage. Only later did the more sophisticated versions that do things like "cut down clocks to prevent temps from rising further" appear.

On desktop PCs, thermal throttling is often set up as "just a safety feature" to this very day. Which means: the system does NOT expect to stay at the edge of its thermal limit. I would not trust thermal throttling with keeping a system running safely at a continuous 100C on die.

100C is already a "danger zone", with elevated error rates and faster circuit degradation - and there are only this many thermal sensors a die has. Some under-sensored hotspots may be running a few degrees higher than that. Which may not be enough to kill the die outright - but more than enough to put those hotspots into a "fuck around" zone of increased instability and massively accelerated degradation.

If you're relying on thermal throttling to balance your system's performance, as laptops and smartphones often do, then you seriously need to dial in better temperature thresholds. 100C is way too spicy.

What does room temperature have to do with any of this? Yes, you can lower your CPU temperature by lowering your room temperature. But you can also lower your CPU temperature by a variety of other means; particularly by improving case airflow. CPU temperature is the interesting metric here, not room temperature.

No but it's also important to realize that this CPU was running at an insane temperature that should never happen in normal operation. I have a laptop with an undersized fan and if I max out all my cores with full load, I barely cross 80. 100 is mental. It doesn't matter if the manufacturer set the peak temperature wrong, a computer whose cpu reaches 100 degrees celsius is simply built incorrectly.

If nothing else, it very clearly indicates that you can boost your performance significantly by sorting out your cooling because your cpu will be stuck permanently emergency throttling.

No it does not. Which part of the text do you feel explains this?

And those mobile devices have much more conservative limits, and much more aggressive throttling behavior.

Smartphones have no active cooling and are fully dependent on thermal throttling for survival, but they can start throttling at as low as 50C easily. Laptops with underspecced cooling systems generally try their best to avoid crossing into triple digits - a lot of them max out at 85C to 95C, even under extreme loads.

I've not looked at the specifics here - but "stable at X degrees, Y% duty cycle, for Z" years is just another engineering spec.

Intel's basic 285K spec's - https://www.intel.com/content/www/us/en/products/sku/241060/... - say "Max Operating Temperature 105 °C".

So, yes - running the CPU that close to its maximum is really not asking for stability, nor longevity.

No reason to doubt your assertion about gaming laptops - but chip binning is a thing, and the manufacturers of those laptops have every reason to pay Intel a premium for CPU's which test to better values of X, Y, and Z.

I do. I've been buying Intel for the same reason as the author: I build machines that don't have glitches and mysterious failures and driver issues and all the rest of the garbage one sees PC assemblers inflict on themselves. Make conservative choices and leave ample headroom and you get a solid machine with no problems.

I've never overclocked anything and I've never felt I've missed out in any way. I really can't imagine spending even one minute trying to squeeze 5% or whatnot tweaking voltages and dealing with plumbing and roaring fans. I want to use the machine, not hotrod it.

I would rather Intel et al. leave a few percent "on the table" and sell things that work, for years on end without failure and without a lot of care and feeding. Lately it looks like a crapshoot trying to identify components that don't kill themselves.

Depends on your priorities. That "performance on the table" might also be called "engineering safety factor for stability".

7900X same. System uptimes of 1month+ often and nearly always runs at 5.0Ghz. Never goes above 80c or so either.

Same for 9800X3D here, which is basically the same CPU. Watercooled. Silent. Stupidly fast.

The 7000 series of CPUs is NOT known for running cool, unlike the AMD 5000 series (which are basically server CPUs repurposed for desktop usage). In the 7000 series, AMD decided to just increase the power of each CPU and that's where most of the performance gains are coming from - but power consumption is 40-50% higher than with similar 5000-series CPUs.

Most definitely - you should always do your own stress testing with your specific CPU (and system) to find out what's stable.

And while all core CO might not be optimal, based on personal experience and what I've seen across multiple enthusiast communities, more often than not you can get an worthwhile improvement to temps/perf with an all core CO.

That being said, there are certainly ways to find and set the best CO values per core, but it will certainly take more effort, stress testing and time.