If you are into technology or even use it for different purposes daily, you have probably heard of two industry titans that provide the CPU and many other products for your personal computers.
These companies are called Intel and AMD.
It is possible that you know more about Intel than AMD since Intel was more dominant in the market in recent years, but is it still dominant?
The first question that comes to mind is: "How are they different?"
In this blog, I will answer that question and explain what makes them different.
Understanding How CPUs Work
To be able to evaluate and compare different types of CPUs, first, we need to understand how the central processor unit(CPU) works.
Basically, each type has multiple registers to hold different values and do different operations on them. In simpler words, if you know how RAM works with the memory units, is similar to the CPU register, except CPU registers are much faster.
A common question after learning this is: "Then why don't they just have more registers and get rid of the RAM?"
CPU is a highly complicated and expensive unit, therefore it is much more expensive to have more registers rather than have a large RAM.
That is one of the reasons that CPUs have a limited number of registers.
There is also a CPU cache that is bigger in size, but also volatile and high speed and it will help the CPU with its frequent operations.
Number of Registers in the CPU
As I mentioned before, there are different types of CPU manufacturers.
AMD and Intel have different approaches to creating their CPUs and this is where they become different.
Calculating all different CPU registers is not an easy task, so here we are only going to compare the number of general-purpose registers in these CPUs.
Arm is the architecture created by AMD and uses 37 general-purpose registers,
meanwhile, X86_64 Intel architecture has 64 General purpose registers.
To get a good idea, you can compare these numbers, with the number of 6502 CPUs (which was introduced in 1975).
6502 CPUs had only 3 registers!
Traditionally speaking, X86 architecture aims for higher performance with lower power efficiency while arm architecture has a better power efficiency with lower performance compared to X86.
Instruction Sets
Another main difference between these 2 architectures is their approach to using instruction sets.
There are two main approaches to using instruction sets: RISC & CISC
RISC is Reduced Instruction Set Computing which is mainly used by arm.
CISC is Complex Instruction Set Computing which is mainly used by X86
The complexity of the instruction has the most effect on the performance and power efficiency of the CPUs.
This is the main reason that Intel X86 architecture is famous for its better performance and lower power efficiency.
Arm's DynamIQ Efficiency Boost
The general idea of this arm architecture feature is to use the bigger CPU cores for demanding applications while smaller, power-efficient cores can be used for the background task.
DynamIQ was a huge win for AMD in the smartphone market since background tasks are taken for granted in smartphones and they require better power efficiency.
Intel came up with a similar idea that couldn't compete since it was not as energy efficient as AMD's DynamIQ.
All this being said, at this time, the world's most powerful supercomputer runs on arm which is called Fugaku.
Software Compatibility
Previously, arm was only dominant in the smartphone industry with its type of engineering, but in recent years it has been showing promise in the PC market too.
This means that a lot of applications and software need to adapt themselves both to remain in demand and useful.
For new developing software, the best way is to compile native software for both architectures. This is also possible for older software that is willing to go through recompilation.
Generally speaking, native compilation helps the software with its performance, but there are also code emulations.
Native software on one architecture can emulate their code to make it compatible with the other architecture, but it may not be as fast as the architecture that was natively compiled.
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