ARM Vs Intel

In the computer processor industry ARM and Intel are big competitors. ARM is based on RISC and Intel processors are based on CISC. As mentioned last post, ARM architecture is mainly used in smartphones and portable devices.

ARM based chips concentrate on high performance while Intel processors aim for low power devices. The processors that provide good ratio of both, will be a winner.

From last week's study, I understood that semiconductor companies buy licence from ARM and develop their own software on chip (SoC). So it's a big completion for Intel. Still many believe that x86 architecture is so mature that it will survive through the competition. My next study will be microarchitecture that makes difference in ARM and Intel processors.

ARM architecture

ARM architecture has RISC based computer processors. Now a days, in majority of smartphones, televisions and mobile controllers chips based on ARM architecture are used. Benefits of RISC like low cost, less heat and low power usage provides main use to portable devices. Semiconductor companies buy license for ARM architecture to design their own system.

In ARM architecture, to compensate for the simpler design, compared with processors like the Intel 80286 and Motorola 68020, some additional design features were used in addition to RISC features. These features are conditional execution, link register, powerful index addressing mode and PC-relative addressing. “Thumb instruction set” improves compiled code density and has 16 bit instructions. “Thumb-2” has 32 bit instructions and can provide variable length instruction set.

RISC and CISC (continued...)

Advantages of RISC over CISC are their speed, smaller chip designs, less cost and can be designed more quickly.

Despite of RISC advantages, RISC was not adapted as processor developers were unable to manufacture RISC chips in large enough volumes to make their price competitive. Also, Intel is a big company using CISC chips. Intel spends lots of money for chip development and research.

I came across Intel’s white paper “Migration from UNIX/RISC and Mainframe to Intel-based Solutions”. They claim that many companies have benefited by migrating to Intel processor in terms of flexibility, lower costs and reliability. I need to find out is it necessary or rather is it really beneficial?

RISC and CISC

At the start of independent study for the topic “Comparison of RISC and CISC architecture on Cloud computing Infrastructure”; I decided to go through basics about RISC and CISC architecture to brush up my knowledge.

I read few articles and here is the outline:

CISC (complex instruction set computer) as the name suggests has complex instructions. The main goal is achieving task in less number of instructions. Emphasis is on hardware that understands and performs instruction. RISC (Reduced instruction set computer) emphasize on software and has simple instructions that can be executed within one clock cycle.