knowitall

AppleInsider said:

Differences between ARM and x86 chips

ARM chips are much more power-efficient than Intel x86 chips, and generally offer better performance-per-watt. That's due to a variety of reasons, including a simpler instruction set, the use of fewer transistors and overall slower clock speeds.
...

x86 processors execute x86 instructions by translating to an internal RISC format (or micro operations) like earlier processors did.
ARM processors have no such translations because the instructions are already RISC.
Internal hardware translation is of course very inefficient (I used to choose assembly instructions that executed in 1 cycle when programming in assembly for such processors) and apparently done by Intel to be able to change processor backend hardware at will (designers flexibility at the cost of processor complexity and performance).
Compilers that target x86 assembly have a problem choosing specific instructions because Intels hardware backend has a fuzzy execution of specific instruction combinations and cannot be predicted performance wise (logically it should pan out, but I'm not 100% sure about that).
Intels x86's try to do way too much predicting code and scheduling instruction parts, confusing compilers which reduces the efficiency even more.
ARM doesn't need al this.
As a consequence Intels x86 processors burn power while ARM sips it.

Another important performance difference has to do with chip fab production. Intel has its own fabs (which cost billions of dollars) and have long be the feature size champion (size in nm of transistors on chip). They thus where able to produce reasonable fast complex processors because others produced chips with a larger feature size (and chip speed, density and watts all go up, up and down quadratically inversely proportionally to the feature size).
A few years ago TSMC became feature size king, because ASML sells them the best UV waver stepper fabs, thus ending Intels reign.

Spot on!!!

bestkeptsecret said:

commentzilla said:

Ok, so now I'm not buying a Mac and will have to wait another  year for the ARM Mac!

If there is no urgency, you can wait. ARM Macs are one thing, but the decider would be if all the software you use is also ported.

Office probably would, given how Microsoft now seems pretty proactive in that regard. But there definitely will be teething problems with respect to software.

Not so. Assembly level (binary) software translation can do that. All software will be available from the start.

Nice info. Interesting.
I myself cling to old hardware as much as possible.
My iMac 27” late 2009 is functioning better than ever running Cor ... eh. Catalina thanks to dosdude1 (very valuable Guy, I donated some money because his work is very very good).
Of course, to be able to use it until now required some essental updates years ago.
I first upgraded RAM memory, and later maxed it out to 16GB. 
Later I replaced the HD by a 1TB solid state drive, which made a really big difference.
I recently tried to use my iMac display for my new rock64, but to no avail.
I now run its desktop via screen sharing and that is really good enough do do server maintenance and things like that.
 

I don’t seem to remember a remark Musk made about lidar ...