Is the Intel "silicon degradation" problem real? Is there any chance this is also around the corner for AMD?
Yes and Intel has confirmed it. It should be fixed now but too high voltages can damage CPUs permanently so it probably means a lot of warrabty claims
See https://www.tomshardware.com/pc-components/cpus/intel-cpu-in...
The problem is unlikely to be around the corner for AMD since they do not have to supply as much voltage to their chips as as Intel to keep up since they are - at least when it comes to x86 chips - currently leading in performance and power efficiency
At higher frequencies (during a frequency boost phase for example) signal quality in the digital signals degrades, because the "stable 1" or "stable 0" plateau is shortened and the "maybe 1 or 0" phase in between stays the same. So a signal that is supposed to be as rectangular as possible gets smushed down towards a sinus, and then smushed even further towards lower amplitudes.
One measure against this is of course better (faster) transistors, such that the "maybe" phase is shorter, but that only works by replacing the hardware. The other measure, which you can do during runtime, is to increase the signal amplitude by increasing the voltage. Then even a degraded signal close to the transistors' maximum switching frequency gets over the "stable 1" and "stable 0" thresholds fast enough.
With a lower supply voltage you can thus not clock the CPU as high as before which is important in boost phases during high load. Which would decrease peak performance in standard desktop and server workloads, and decrease overall performance in compute-intensive workloads. Or if you still clock it as high as before, signal quality will be lessened, increasing the probability of bit errors, lessening system stability and reliability of results.
Which direction intel will pick for this firmware upgrade, degraded-performance, degraded-stability or degraded-both, I don't know, I guess we'll see.
Unless I missed a real investigation posted somewhere?
... unless you're using EXPO/XMP. I would really recommend people who run automatically overclocked memory taking a closer look at how much voltage the motherboard is pushing into your CPU, especially into the SoC. Some motherboards just push the voltages to the absolute permitted maximum; ASUS is particularly bad at this. I run lower RAM frequencies than my system is capable of because I haven't seen much performance improvement above 5600 "MHz", and it can be made to run at almost stock voltages.
It definitely causes faster silicon degradation; the question is how fast it will kill the processor. Both Intel and AMD have shown us that it can happen very quickly, not in the course of several decades as we've assumed for the longest time.
It just used to be jumpers and dip switches, then the BIOS before some of it moved into the CPU itself.
>Intel also confirmed a rumored issue with via oxidation in its 7nm node, but said those issues were corrected in 2023 and didn't contribute to the failures.
Do you trust Intel to not lie about a widespread unfixable problem?
https://www.tomshardware.com/pc-components/cpus/intel-finall...
Walking the line of "well, we didn't say..." is one thing but if they say the oxidation issue was ended in may 2023 then I don't see a reason to doubt that.
This is a complex problem with several interacting causes and failure modes, and assuming that oxidation is the cause of all of them (that there exist chips not during the oxidation defect window that failed, therefore the oxidation defect window must be larger) is circular reasoning.
When you draw more current - i.e. make the chip do work - the voltage drops. "Load line calibration" was introduced as a way to crank the applied voltage up as the chip worked harder to offset this. Alternatively phrased, if you set the voltage so that it works well under load, it's kind of set too high for idle, so LLC gives a way to decrease idle voltage.
There was some discussion at the time about the wisdom of this. The voltage rings when you change it (overshoots), and it's not that clear whether high voltage at idle matters very much (since the chip is cooler then). I remember reading a bunch of articles, then some materials science books, then turning off LLC in the bios as probably a misfeature.
The current Intel problem is they've built a reputation on being the fastest and the most reliable CPU. Then they lost fastest to chiplets at AMD, so adjusted to "fastest single core". They really didn't want to lose that too, and CPU's run faster when you push more voltage through them, so that's what they did.
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"Intel silicon degradation" currently refers to people noticing that desktop processors from the last couple of generations were degrading, despite not being overclocked. Some finger pointing there, Intel encourages motherboards to set fairly aggressive out of the box controls because it looks good under review. Also some more recent reports that mobile chips have the same behaviour. At a guess, the desktop ones have the voltage too high and the mobile ones are running at much higher temperature. Some reports are mentioning LLC which would be personally satisfying if it turns out to be the root cause.
I'm waiting to see if reports of degradation start to emerge on the Xeon line. Intel is claiming there's no risk of that but they're made out of the same magic sand and under really heavy competitive pressure from the Epyc chips. They've also got rather high power consumption relative to previous generations.
As to whether the same thing will hit AMD - probably not. If you take one of their chips and push the voltage up, yeah, it'll have the same degradation over time. But they're not running out of the box at the edge of feasible to try to cope with the competition because chiplets are winning the day. Also AMD doesn't have the gilded reputation of Intel to rely upon if reliability comes under question. The incentives are pointing in the opposite direction.