In addition, the speed meant they needed very long pipelines. Sometimes the electrical signals couldn't propagate across the chip fast enough and instructions would be stuck in essentially a wait stage of the pipeline.
IOW, this idea ran very hot, and wasn't very efficient. Remember, the first Pentium 4 with this architecture did less work than a Pentium 3 of the same clock speed.
If I get it right, the purpose of the multiple cores was to increase the yield of functional CPUs.
That showed up on AMD's three-core chip. This calculation is also the reason the PS3 has only seven of the eight processing units enabled. They disable one even if all eight are good.
But usually the yield quality determines clock speed. Lower quality produces lower clock speed. This was also a reason for the switch, as Intel couldn't get good yields on the high-speed processors, resulting in a glut of many lower speed ones for very few capable of the highest speeds as they were pushing the technology.
. Moore’s law has already broke down.
Moore's law is often misunderstood. Moore said "The complexity for minimum component costs has increased at a rate of roughly a factor of two per year." He predicted this to last 10 years, after which he changed it to every two years (not 18 months).
Seeing the actual definition, it's clear that Moore's Law is alive and well. Two cores being put in a chip for the same cost as a single core two years ago perfectly represents Moore's Law.
yield determines unit cost. the ones that meet spec are paying for the ones that don’t. Therefore, multi-cores is a strategy for hedging against moore’s law. Your 7 out of 8 discussion only proves my point, not yours.