> Because of this excess baggage, an x86 chip needs more
> transistors than its ARM-based equivalent, and thus it
> consumes more power and must dissipate more heat.
This is true but it ignores the primary reality of "desktop class" processor design today: RAM is the bottleneck in a really major way and most of a desktop class CPU's transistors are dedicated to overcoming this.In the ancient days, CPUs ran synchronously (or close to it) with main memory. Hasn't been that way for decades. CPU performance has ramped up so much more quickly than that of main memory that it's ridiculous.
And this is where most of your transistors are spent these days - finding ways to allow the CPU to do some useful work while it sits around waiting for main memory. Look at a modern i5 CPU die:
https://www.google.com/search?q=intel+core+i5
Things to note: - Tons of L1/L2/L3 cache so we can keep things in fast memory. The transistors dedicated to cache dwarf those allocated to the actual processing cores, let alone the parts of those processing cores dedicated to those crufty ol' x86 instructions - Lots of transistors dedicated to branch prediction and speculative execution so we can execute instructions before we've even waited around for the data those instructions depend upon to arrive from slow-ass main memory
Sure, mobile ARM chips are tiny and efficient! They run at 1-2GHZ while paired with fast RAM that's not that much slower than their CPUs. They don't need to devote gobs and gobs of transistors to speculative execution and branch prediction and cache.
But all that changes if you want to scale an ARM chip up to perform like a "desktop-class" Intel chip. You want to add cores and execution units? If you want to keep them fed with data and instructions you're going to need all that extra transistor-heavy baggage and guess what -- now you're just barely more efficient than Intel, and you can't match Intel's superior process technology that's been at least a transistor shrink or two ahead of the competition since the dawn of the semiconductor industry.
Eventually, yes, the ARM chip makers will solve this. RAM will get faster and processes will be enshrinkified. Just understand that transistor size and pokey RAM are the bottlenecks, not that nasty old x86 instruction set.