ARM, previously Advanced RISC Machine, originally Acorn RISC Machine, is a family of reduced instruction set computing (RISC) architectures for computer processors, configured for various environments. ARM Holdings develops the architecture and licenses it to other companies, who design their own products that implement one of those architectures—including systems-on-chips (SoC) and systems-on-modules (SoM) that incorporate memory, interfaces, radios among others
What is Instruction Set?
The complete set of all the instructions in machine code that can be recognized and executed by a central processing unit. (Google)
The difference between RISC and CISC is that the former uses simple instructions spanned in multiple lines, each of which is executed during one compute cycle. On the other hand, in CISC, a single line complex instruction comprised of multiple tasks is used, this consumes power and reduces efficiency.
Difference Between CISC & RISC
CISC(complex instruction set computation) is adopted by INTEL and AMD.
RISC processors consume less power due to simple instruction set, while CISC CPUs consume more power due to complex one-line instructions.The X86 CPUs like Intel and AMD use a mix of RISC/CISC hybrids while ARM CPUs utilize RISC to conserve power and offer better battery life.
Intel Atom used to be a thing as the mobile processor started its journey on some smartphones but ended up receiving no proper app support. The Intel processor was overthrown by the sheer number of ARM-based mobile chips, prompting developers to develop apps native to ARM. Intel’s System-on-chip mobile CPU(Atom) keep declining as ARM produces chips that are smaller, faster and more energy efficient.
The architect of the smartphone era, ARM authors the instruction sets and blueprint core designs for mobile systems-on-a-chip (SoC) as well as systems-on-module (SoM), which companies like Qualcomm, Apple, Samsung, and (until recently) Huawei then license and develop into products that power iPhones, Galaxy’s, and Pixels. The newly unveiled Cortex-A77 CPU and Mali-G77 GPU are refreshingly simple in that they’re all about increasing performance and efficiency without doing much in the way of adding features or specialist capabilities. The ARM instruction set was basically developed to take maximum advantage of CPU power when processors only had a few million transistors. In 2019, however, a normal smartphone chip consists of around 6 billion transistors.
This was the reason why ARM was held back during its early days. People wanted a more powerful desktop and efficiency wasn’t a concern because PCs don’t use batteries.
All of it changed when smartphones arrived. These phones needed a CPU which was efficient as battery usage was a concern for the mobile user. ARM has made a fortune in designing CPUs for smartphones and continues to do so. However, The ARM instruction set was basically developed to take maximum advantage of CPU power when processors only had a few million transistors. In 2019, however, a normal smartphone chip consists of around 6 billion transistors.
ON THE PC-LAPTOP SIDE WITH ARM
Qualcomm Snapdragon 8cx
At the moment, Snapdragon 835 and 850 have been used in laptops. They offer around 20-hours of battery life but with the performance of a smartphone. These laptops functioned like an always-on PC similar to a smartphone. Snapdragon 8cx seeks to bridge that gap by providing a high level of performance and good battery life. The Snapdragon 8cx is an ARM processor designed specifically by keeping laptop performance requirements in mind. It will also feature LTE support, courtesy of the Snapdragon X24 modem inbuilt in the processor’s dye.
Microsoft launches ARM-powered Windows machine
HP’s first Windows 10 ARM PC
Asus’ next Windows 10 ARM
A crop of Windows 10 laptops that run atop Qualcomm Snapdragon ARM processors are available from major PC makers.
Notebooks such as the HP Envy x2 and Asus NovaGo, though novel, and offering crazy-long battery life.
The project supports three ARM laptops at present, all of which run on the Qualcomm Snapdragon 835 chip:
1.HP Envy x2
3.Lenovo Miix 630
4. HUAWEI NOTE BOOK
ON THE SERVER SIDE WITH ARM
On the server side, Amazon Web Services (ASW) recently announced ARM-based server-side CPUs for Virtual machines. Meaning, users will be able to use AWS virtual performance powered by an ARM-Processor instead of an Intel one. Amazon announced the new “A1” instance type for the Elastic Compute Cloud (EC2) that is powered by their own “Graviton” ARMv8 processors.
Furthermore, the server-side ARM CPUs are faster than Intel Xeon E5 processors. In a program to find 12 million prime numbers, the Intel CPU took 9.8 seconds while the ARM CPU did it in 8.9 seconds.
AWS is also offering the instances of ARM-based virtual machines cheaper when compared to Intel-powered ones.
In this case, the CPU comparison reveals entirely new results. One that could spell the end for Intel.
ARM’s DEIMOS AND HERCULES TO OVERTHROW INTEL
PC makers like Asus and HP beginning to design laptops and tablets around ARM chips, ARM itself has decided to emerge from the shadows and unroll its roadmap to challenge Intel through at least 2020.
ARM’s now-public roadmap represents its first processors that are designed for the PC space. ARM, taking aim at the dominant player, claims its chips will equal and potentially even surpass Intel’s in single-threaded performance.
ARM is unveiling two new chip architectures: Deimos, a 7nm architecture to debut in 2019, and Hercules, a 5nm design for 2020. There’s a catch, of course: Many Windows apps aren’t natively written for the ARM instruction set, forcing them to pay a performance penalty via emulation.
The company has offered a rare peek at the performance expectations for its future processor architectures, and the figures might make Intel nervous. While ARM already believes that its recently unveiled Cortex-A76 is competitive with Intel’s 2.6GHz Core i5-7300U, it expects its 2019 “Deimos” and 2020 “Hercules” designs to clearly outperform that CPU. You would get “laptop-class” speed from a more efficient mobile chip, according to the company.
ARM processors are RISC based. Which means that their architecture incorporates less clocks per Instruction. Whereas the CISC processors such as Intel, use a higher clock rate to speed thigs up.
Intel CPUs deal with greater clocks per instruction thereby requiring greater power consumption.
The new ARM cortex are more energy efficient than new Intel Atom processor But only in terms of GHz/ W, but it is only a simple 32 bit RISC, whereas Intel has a powerful 64 bit CISC architecture.
Intel x86 processors can deliver up to 3.6 GHz while consuming up to 130 W, or at the low end 1.8 GHz at 40 W. The ARM line of chips has been reported to deliver 1 GHz at 700 mW  (down by x50 in terms of GHz/W) and can reach up to 2 GHz; while still consuming less than a watt (down by x 75 in terms of GHz/W), So the power savings seem to be substantial.
The figures don’t include Intel’s comparable 8th-generation Core chips that pack twice as many cores and could easily shrink the performance gap. This is also based on one synthetic, integer-oriented benchmark (SPEC CINT2006), not a broader suite of tests that would measure floating point math and other performance traits. ARM is putting its best foot forward rather than offering definitive proof.
Even so, it’s telling that ARM might be in the ballpark. There’s already talk of Qualcomm making a truly laptop-worthy Snapdragon in the near future — Deimos and Hercules could be fast enough that you might choose an ARM-based PC for a speed advantage, not just longer battery life. And that could give Intel a good reason to panic. It’s still struggling to make 10-nanometer chips at the same time as ARM is talking about 7nm and 5nm parts. If Intel can’t find a way to stay ahead, it may see big PC makers switching to ARM as they look for more powerful options.