Feng's classification

The maximum number of binary digits that can be processed within a unit time by a computer system is called the maximum parallelism degree P. If a processor is processing P bits in unit time, then P is called the maximum

degree of parallelism.{{cite web|last1=Salih|first1=Mariam A. Salih| title=Architectural Classification|url=http://www.uotechnology.edu.iq/ce/lecture14/forth%20class/distributed%20system%20lectuers/L2.pdf|accessdate=5 October 2016}}

Let i = 1, 2, 3, ..., T be the different timing instants and P₁, P₂, ..., P_T be the corresponding bits processed.

Then,

{{block indent| em = 1.5 | text = Average parallelism, P_a = (P₁ + P₂ + ... + P_T) / T}}

Processor utilization $\backslash mu$ is defined as

$$\backslash mu\; =\; \backslash frac\{P\_a\}\{P\}$$

The maximum degree of parallelism depends on the structure of the arithmetic and logic unit. Higher degree of parallelism indicates a highly parallel ALU or processing element. Average parallelism depends on both the hardware and the software. Higher average parallelism can be achieved through concurrent programs.

According to Feng's classification, computer architecture can be classified into four. The classification is based on the way contents stored in memory are processed. The contents can be either data or instructions.{{Cite web |url=https://www.gehucsit.files.wordpress.com/2013/09/handlers-classsification1.pdf |title=Archived copy |access-date=2016-10-05 |archive-url=https://web.archive.org/web/20140701093615/http://gehucsit.files.wordpress.com/2013/09/handlers-classsification1.pdf |archive-date=2014-07-01 |url-status=dead }}

• Word serial bit serial (WSBS)
• Word serial bit parallel (WSBP)
• Word parallel bit serial (WPBS)
• Word parallel bit parallel (WPBP)

One bit of one selected word is processed at a time. This represents serial processing and needs maximum processing time.

It is found in most existing computers and has been called "word slice" processing because one word of one bit is processed at a time. All bits of a selected word are processed at a time. Bit parallel means all bits of a word.

It has been called bit slice processing because m-bit slice is processed at a time. Word parallel signifies selection of all words. It can be considered as one bit from all words are processed at a time.

Fully parallel processing involves simultaneously processing an array of `n × m` bits. This means that both `n` words and `m` bits in each word are processed at the same time, enabling faster and more efficient data handling.

It fails to project the concurrency in pipeline processors, as degree of parallelism doesn't account for concurrency handle by pipe-lined design.

• Händler's {{ill|Erlangen Classification System|de}} (ECS)
• Flynn's taxonomy

{{Reflist}}

Category:Computer architecture