Moore’s Law is Dead shared an interesting video yesterday about these chips. Supposedly, leaks from his sources at Intel say that high voltages being pushed through the ring bus cause degradation. The leaks claim it shares the same power rail as the P and E cores, meaning it’s influenced by the voltage requested by the cores.
For context, the ring bus is responsible for communication between cores, peripherals, and the platform. This includes memory accesses, which means that if the ring bus fails and does something incorrectly, it could appear normal but result in errors far down the line.
Going beyond the video specifically, and considering what others have suggested as workarounds, it seems like ring bus degradation might be a decent candidate for the actual root cause of these issues.
Some observations around chips degrading were:
High memory pressure exacerbates the issue.
Chips with more cores deteriorate faster.
Some of the suggestions to work around the issue were:
Lower the memory speed.
Lower the voltage and clock speeds.
Disabling E cores.
All of those can be related to stress being put on the ring bus:
Higher voltage being put through the bus -> higher likelihood of physical damage
More memory pressure -> more usage of the bus, more opportunity for damage to accumulate
More cores -> more memory pressure
Slower memory speeds -> less maximum throughput -> less stress
I’m not claiming anything definitive, but I think my money is on this one.