Some notes on current state of ARM vs Intel processors.
Background
First ARM processors were manufactured in 1980s but not very popular. Their advantage was low power usage, which was not popular at that time. However in the 1990s, as portable devices found popularity and required low power processors the ARM popularity increased. Such as the Apple Netwon, which used an ARM based chip.
ARM has a different business model than Intel/AMD. ARM Holdings design CPU core architectures which are licensed out to manufacturers such as Apple or Quadcom. The manufactures use the architecture design for their applications. The designs are often extended by these manufacturers.
Popular processors such as NVIDIA Tegra and Qualcomm Snapdragon are based off ARM architectures. IBM’s Watson uses a RISC architecture like ARM but is not ARM – its called Power7 designed in house by IBM.
AWS has released EC2 servers using ARM based architecture chips. These are server specific CPUs and one of the first cases where a non x86 based chip is being used. The new AWS ARM chips are 64 bit, just like Intel Xeons which are often used for similar Ec2 servers. And like the intel chips, these ARM chips have been specifically designed by AWS to have high focus on performance.
There have been many comparisons done on what the differences look like for these new AWS EC2 ARM based servers. Thus far, the ARM servers perform as well if not better than x86 based servers. Since these ARM processors use less power (which is good for AWS) they cost less than an x86 based server. This is a considerable threat for Intel.
CISC vs RISC
Intel x86 is a CISC (complex instruction set computer) based architecture. ARM is RISC (reduced instruction set computer) based architecture. CISC allows variable instructions and therefore can handle more dynamic workloads whereas RISC has set instruction sizes. However the flipside of this is that RISCs more granular instruction handler provides more control which can be useful for things like optimization. This is why for parallel computing RISC based architecture can be more advantageous.
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