Bit Level Parallelism

Adwit
6 min readDec 7, 2022

--

What is Parallelism?

The process of solving computer programmes and difficult problems by breaking them down into smaller jobs is known as parallelism or parallel computing. Processors are components of computers that are utilised to tackle challenging issues. The work is broken up into smaller pieces and completed all at once.

visualisation of parallel and serial computing

The concept of a single data centre with many data centres built in different pieces is known as parallel computing. The calculation request is sent to the application server in small bits as it comes in, and the problem is then addressed concurrently. Utilizing the available computer capacity to tackle challenging application issues and processing is the primary objective of parallel computing, and in particular bit-level parallelism.

Examples of Parallel Computing

Parallel computing is a constant in our day-to-day activities. Despite being decades old, the idea is becoming more and more widespread and appropriate to the contemporary, more digital environment. It may be accessed at any time, whether while working or monitoring the weather or traffic.

Think about the non-technological tasks you perform at the same time every day to help you grasp the notion. For instance, there are numerous checkout lanes at the grocery store, as well as self-service checkout counters that can handle many customers concurrently. On the other hand, paying for goods in a single lengthy queue would be tiresome and time-consuming for both consumers and personnel.

Perhaps you run the coffee maker in the morning while preparing lunch as you get ready for work. This is a type of parallelism as well since you are working on two things at once rather than waiting for your coffee to brew before starting on your lunch because it would be ineffective.

Bit-Level Parallelism

A type of parallelism that refers to the size of the data the processor can process is known as bit-level parallelism.

It is a form of parallelism which is based on the increasing processors word size. It shortens the number of instructions that the system must run in order to perform a task on a variables which are greater in size.

Take an 8-bit CPU, for instance, adding two 16-bit numbers as an example. The CPU had to add the 8 lower-order bits from each integer first, then add the 8 higher-order bits, and then execute two instructions to finish the task at hand. The procedure might be finished with a single instruction on a 16-bit CPU.

Serial (single-bit) computers were the first type of electronic computers. The 16-bit Whirlwind from 1951 was the first electronic computer that wasn’t a serial computer — the first bit-parallel computer. As 4-bit microprocessors were replaced by 8-bit, then 16-bit, then 32-bit microprocessors from the 1970s, when very-large-scale integration (VLSI) computer chip fabrication technology first appeared, until about 1986, advancements in computer architecture were made by increasing bit-level parallelism. With the advent of 32-bit processors, which dominated general-purpose computing for 20 years, this trend essentially came to a stop. With the release of the Nintendo 64, 64-bit architectures entered the public consciousness. However, until the launch of the x86–64 architectures in 2003 and the ARMv8-A instruction set in 2014, 64-bit architectures remained a rarity. The external data bus width on 32-bit CPUs keeps growing. DDR1 SDRAM, as an illustration, transmits 128 bits each clock cycle. DDR2 SDRAM transmits 256 bits at the very least every burst.

Problems with Bit Level Parallelism

In the real world, we have to contend with fundamental issues like driver loading issues, hardware limits, and speed trade-offs. Compared to the simplest logic gate, driving a very big truth table constructed of PLA would significantly slow down its cycle time. Even though we have a lovely parallel description of our issue, we cannot implement it in a single cycle of the bare minimum logic gate delay. The performances of various circuits in fan-in restricted circuitry are really predicted by the Winograd theorem. However, this bit-level (gate level) study demonstrates its improvements over previous coarser grained analyses. Some of his conclusions are extremely fascinating and not so obvious.

Bit-level parallelism is reduced and optimised by use of a variety of challenges. Although they did not use the phrase “bit-level parallelism,” early logic designers were indeed faced with this issue. There are fewer gates in early logic designs, but there are more fan-outs and longer minimum gate delays. However, serial and parallel adders are already well-known, but because of the issues with overusing their methods, relatively few customers had to turn to lower lever logic architectures when microprocessors were launched. Techniques have never been the major issue because they are very simple to use but time- and resource-consuming to complete. The reason they ultimately lost out to computers is that they are not adaptable or sophisticated. The utilisation of these strategies is the fundamental issue. In contrast to the coarser grained parallelism, they now have a more trustworthy and solid theory to describe their circuitry thanks to information theory. We can incorporate intelligence into logic gate designs by comprehending what intelligence actually is.

Coarse grained parallelism outperforms bit-level parallelism in terms of research articles published. For instance, the ESPRIT software, which has yet to be used and commercialised, is essentially data-flow parallelism. Both theoretical and practical issues plague us. Users find it challenging to comprehend the ideas and utilise the parallelism with the instruments at hand. There isn’t much money left for bit-level parallelism since so much money is going towards coarse-grained parallelism everywhere in the globe. The majority of effort on taking use of bit-level parallelism is in VLSI design tools, but they are not specifically made for it.

Neural networks are a significant area of research that, once trained, operate like a truth table, hence they are essentially bit-level parallel architectures (or can be transformed to this form). It should be feasible to create programmable truth tables that can perform neural network-like operations. Understanding the fundamental concepts of intelligence and cognition is challenging. My approach of assessing intelligence simply compares it to random behaviour, but its main contribution is to debunk intelligence and return to the straightforwardness of the scientific process. The current attempts to mimic the human brain are comparable to attempts to fly like a bird, and the participants may include well-known geniuses like Leonardo Da Vinci.

Future of Parallel Computing

What will happen with parallel computing next? By now, it should be obvious that this idea is gaining ground and gradually displacing serial computing due to its effectiveness and enormous popularity. Many of the most well-known IT firms and operating system distributors are embracing the idea as the world continues to change. In the future, parallel computing will enable a faster, more technologically advanced, and interconnected world in which multiple tasks can be completed at breakneck speed.

Conclusion

Bit-level parallelism is easier to design than coarser-grained parallelism, but it hasn’t been widely adopted since it’s difficult to implement the approaches with current tools and technology. DSP, SCOP, and PGA are attempts to make bit-level design use simpler, but intelligence must be incorporated for full exploitation (programmability using high level languages). In contrast to complete gate/bit level design implementations, they are just a middle ground option.

--

--