Back side bus

Back side bus

In personal computer microprocessor architecture, a back side bus (BSB), or backside bus, is a computer bus used to connect the CPU to CPU cache memory, usually L2. If a design utilizes it along with a front side bus (FSB), it is said to use a dual-bus architecture, or in Intel's terminology "Dual Independent Bus" (DIB) [cite web|url=http://www.pcguide.com/ref/cpu/arch/extBackside-c.html|title=Dedicated Backside Cache Bus|publisher=PCguide.com|date=2001-04-30] architecture.

BSB is an improvement over the older practice of accessing the cache over the front side bus (FSB), because FSB is typically a severe bottleneck in modern systems. In addition, due to its dedicated nature, the back side bus can be optimized or customized for communication with cache, thus eliminating protocol overheads and additional signals that are required on a general-purpose FSB. Furthermore, since a BSB operates over a shorter distance, it can typically operate at higher clock speeds, increasing the computer's overall performance.

Cache connected with a BSB was initially external to the CPU silicon chip, but now is usually on-chip. [cite web
url=http://www.itworld.com/Comp/1091/CWD010430STO60015/
title=Buses: frontside and backside
publisher="ITworld"
date=2001-04-30] In the latter case, the BSB clock frequency is typically equal to the processor's,fact|date=September 2007 and the back side bus can also be made much wider (256-bit, 512-bit) than either off-chip or on-chip FSB.

The dual-bus architecture has been used in a number of chips, including the IBM and Freescale PowerPC processors (certain PowerPC 604 models, the G3 line based on the PowerPC 750 [cite web|url=http://news.com.com/Monday+a+big+day+for+Apple/2100-1001_3-205119.html|title=Monday a big day for Apple|publisher=CNet|date=1997-11-07] , and the Freescale G4 line), as well as the Intel Pentium II processor [cite web
url=http://searchstorage.techtarget.com/sDefinition/0,,sid5_gci213804,00.html
title=Backside Bus
publisher=Whatis.com
date=2001-04-30] , which used it to access their L2 cache (earlier Intel processors accessed the L2 cache over the FSB, while later processors moved it on-chip).

ee also

*CPU cache
*Computer bus
*Front side bus

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Back-side bus — Saltar a navegación, búsqueda En el mundo de la computación personal, el Back Side Bus (BSB, literalmente “bus trasero”, en contraposición al frontal o FSB) se refiere a la conexión entre un microprocesador y su memoria cache externa, en… …   Wikipedia Español

  • Back side bus — (BSB)  шина кэш памяти второго уровня в процессорах с двойной независимой шиной (англ. DIB dual independed bus). Для связи с контроллером памяти предназначена FSB (front side bus), работающая в качестве магистрального канала между… …   Википедия

  • Front-side bus — Este artículo o sección necesita referencias que aparezcan en una publicación acreditada, como revistas especializadas, monografías, prensa diaria o páginas de Internet fidedignas. Puedes añadirlas así o avisar al auto …   Wikipedia Español

  • Front side bus — In personal computers, the Front Side Bus (FSB) is the bus that carries data between the CPU and the northbridge.Depending on the processor used, some computers may also have a back side bus which connects the CPU to the cache. This bus and the… …   Wikipedia

  • Front Side Bus — (FSB)  шина, обеспечивающая соединение между x86 совместимым центральным процессором и внутренними устройствами. Как правило, современный персональный компьютер на базе x86 совместимого микропроцессора устроен следующим образом:… …   Википедия

  • Front side bus — FSB (англ. Front side bus, переводится как «системная шина») компьютерная шина, обеспечивающая соединение между x86 совместимым центральным процессором и внешним миром. Как правило, современный персональный компьютер на базе x86 совместимого… …   Википедия

  • Bus posterior o BSB — Saltar a navegación, búsqueda Es una interfaz similar a FSB pero está en ámbito de memoria caché. Refiriéndose a la arquitectura de microprocesadores de computadoras, un bus posterior (BSB) o back side bus es un bus o interfaz que interconecta la …   Wikipedia Español

  • Bus (computing) — 4 PCI Express bus card slots (from top to bottom: x4, x16, x1 and x16), compared to a 32 bit conventional PCI bus card slot (very bottom) In computer architecture, a bus is a subsystem that transfers data between components inside a computer, or… …   Wikipedia

  • System bus — Example of a single system computer bus A system bus is a single computer bus that connects the major components of a computer system. The technique was developed to reduce costs and improve modularity. It combines the functions of a data bus to… …   Wikipedia

  • Bus advertising — Buses and their related infrastructure is a medium commonly used by advertisers to reach the public with their message. Usually this takes the form of promoting commercial brands, but can also be used for public campain messages. Buses may also… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”