What's so bad about Intel 8086 in technical terms?

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Ironically, the x86 has been developed into the fastest consumer processor while the 68k was dropped after only 1 major ISA update.

Not sure if the AMD64 really counts as x86... I know it has full x86 compatibility, but the ISA is so far removed from the old x86 design, I would call it a new architecture.

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The original Core Duos were basically two Pentium 4s on a chip, the i series developed out of this but fixed many of the pentium core issues, but yeah, somewhere deep in the cores lie remnants of the old 8086...

Actually the CoreDuo and later processors were develops from the Pentium M... Which was itself developed from the Pentium III. The Pentium 4, known as netburst was discontinued.

I doubt there is anything of the 8086 in there, except the real mode emulator that the chip boots in... Hmmm, that's only true if the system is using an IBM PC compatible BIOS... All my x86 machines use EFI, which AFAIK has no real mode code in it.

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They all boot in real mode, EFI just switches to protected mode within the first few instructions.

Yes, I think you're right, I was wondering if there might be some nonresetable fuses that they might burn at the factory to disable the real mode booting... But I guess it just wouldn't be worth it.

No matter what mode it's in the cpu is executing instructions by translating them. So if you class real mode an emulator then protected or x64 mode is also an emulator.

Emulator isn't the right word obviously, when the CPU is running in whichever mode it's using a decoder for that ISA... I used the term emulator, as I'm not sure how closely the x86-64 architecture maps to the 8086, but a quick glance at the AMD docs shows clearly that a real mode decoder would fit comfortably in there.

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x86 design was good enough for World domination.

Nothing stands in the way of progress more than "good enough".

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Keep repeating that; it won't make it true.

I will quote Neil DeGrasse Tyson: "The good thing about science is that it's true whether or not believe in it".

I'm not sure if your gripe was about the emergence of ARM as the next major processor architecture, or that the PPC is now a dead platform with only a few legacy devices left in the supply chain. Both statements seem reasonable to me, and backed up by the evidence available.

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Most successful things are haphazard. The last successful good design I have seen is the PlayStation, but even that has some hardware bugs that they had to maintain throughout the life of the console because fixing them would hurt compatibility.

It always comes down to the real world vs the perfect world. A concept might be beautiful and elegant. But in the real world, compromises must be made.

Intel have managed to get power usage for their phone chipsets down a lot in the last few years though.

But as you will find if you try a low power intel chip, when they get the power usage down to ARM levels they struggle to offer the performance that ARM can. The converse is also true, as ARM ramp up performance, power usage increases to Intel x86 levels.

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The benchmarks I saw were identical performance with Intel showing lower power usage. Supposedly the problem for Intel today is they haven't got a chipset with 4G support.

I'd be intrigued to see that. I've not seen the ARM bested in power consumption stats.

Arm architecture has changed a lot since the beginning, it's not a simple RISC processor anymore.

Hahahahah, there's no such thing as CISC and RISC anymore, all modern processors are a hybrid of these two concepts.

The best solution to most problems are hybrids.

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Like Windows 8!

Well yes, in a way... Windows does use a hybrid Kernel, that has features of both Micro Kernels and Monolithic Kernels.

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Err no.

CISC chips = can operate on memory.

RISC chips = are load/store machines and can only operate on register.


68K and x86 = CISC

MIPS/POWER/ARM = RISC


Whether your chip is internally hardcoded, or does Microcode or has pipeline has nothing to do with CISC or RISC.

Hahaha, when marketing becomes policy

By your simplistic (though not wholy inaccurate definition), the x86 is actually a RISC machine! Since it's non orthogonal ISA often requires one to load data into Registers for processing and then written back to the main memory.

To be frank, only the MIPS every really fully implemented all the RISC concepts... And look where that is now! I come back to my original statement: modern CPUs have features of both RISC and CISC designs. PPC an ARM are examples of RISC chips that have woefully complex instruction sets, and the x86 is a great example of a CISC chip that has been on a diet to give it RISC like features.

Check out the ARM64 ISA, that is so
Complex it could be CISC, but so carefully crafted for throughput it's clearly RISC in origin!