single-core
A single-core processor is a microprocessor with a single CPU on its die.{{cite web |title=Single-core definition |url=https://www.yourdictionary.com/single-core |website=Your Dictionary |publisher=LoveToKnow |access-date=17 March 2022 |archive-date=15 November 2018 |archive-url=https://web.archive.org/web/20181115213054/http://www.yourdictionary.com/single-core |url-status=dead }} It performs the fetch-decode-execute cycle one at a time, as it only runs on one thread. A computer using a single core CPU is generally slower than a multi-core system.
Single core processors used to be widespread in desktop computers, but as applications demanded more processing power, the slower speed of single core systems became a detriment to performance. Windows supported single-core processors up until the release of Windows 11, where a dual-core processor is required.{{cite web |title=Windows 11 Minimum Requirements |url=https://www.microsoft.com/en-gb/windows/windows-11-specifications |website=Find Windows 11 specs, features and computer requirements |publisher=Microsoft |access-date=17 March 2022}}
Single core processors are still in use in some niche circumstances. Some older legacy systems like those running antiquated operating systems (e.g. Windows 98) cannot gain any benefit from multi-core processors. Single core processors are also used in hobbyist computers like the Raspberry Pi and Single-board microcontrollers. The production of single-core desktop processors ended in 2013 with the Celeron G440, G460, G465 & G470.{{cite web |title=The last single core CPU... |url=http://www.andyscomputer.net/2021/01/the-last-single-core-cpu.html |website=Andy's Computers |date=6 January 2021 |access-date=17 March 2022}}
Development
The first single core processor was the Intel 4004, which was commercially released on November 15, 1971 by Intel.{{cite web |title=Intel's First Microprocessor |url=https://www.intel.com/content/www/us/en/history/museum-story-of-intel-4004.html |website=The Story of the Intel 4004 |publisher=Intel |access-date=17 March 2022}} Since then many improvements have been made to single core processors, going from the 740 kHz of the Intel 4004 to the 2 GHz Celeron G470.{{cite web |title=Intel Celerton Processor G470 Datasheet |url=https://duckduckgo.com/?t=ffab&q=Celeron+G470&atb=v1-1&ia=web |website=Intel Celeron Processor G470 |publisher=Intel |access-date=17 March 2022}}
=Advantages=
- Single core processors draw less power than larger, multi-core processors.
- Single core processors can be made a lot more cheaply than multi core systems, meaning they can be used in embedded systems.
=Disadvantages=
- Single-core processors are generally outperformed by multi-core processors.
- Single-core processors are more likely to bottleneck with faster peripheral components, as these components have to wait for the CPU to finish its cycle.{{cite web |title=How To Properly Balance Your Components |url=https://www.intel.com/content/www/us/en/gaming/resources/what-is-bottlenecking-my-pc.html |website=What is Bottlenecking? |publisher=Intel |access-date=17 March 2022}}
- Single-core processors lack parallelisation, meaning only one application can run at once. This reduces performance as other processes have to wait for processor time, leading to process starvation.{{cite web |last1=Johnson |first1=Ogundairo |last2=Dinyo |first2=Omosehinmi |title=Comparative Analysis of Single-Core and Multi-Core Systems |url=https://aircconline.com/ijcsit/V7N6/7615ijcsit10.pdf |website=aircconline |publisher=International Journal of Computer Science & Information Technology |access-date=17 March 2022}}
Increasing parallel trend
- Single-core{{snd}} one processor on a die. Since about 2012, even most smartphones CPUs marketed are no longer single-core; Microcontrollers are still single-core, while there are exceptions.{{cite web |last1=Yiu |first1=Joseph |last2=Johnson |first2=Ian |title=Multi-core microcontroller design with Cortex-M processors and CoreSight SoC |url=https://community.arm.com/cfs-file/__key/telligent-evolution-components-attachments/01-1989-00-00-00-00-52-92/Multi_2D00_core-microcontroller-design-with-Cortex_2D00_M-processors-and-Cor.pdf |website=ARM Community |publisher=arm.com |access-date=17 March 2022}}
- Multi-core processors{{snd}} a 'few' processors on a die, e.g. 2, 4, 8.
- Manycore processors{{snd}} a 'large number' of processors on a die, e.g. 10s, 100s, 1000s. Some specialist ASICs/Accelerators and GPUs fall into this category.