Editing Front-side bus (section)

==History==
The term came into use by Intel Corporation about the time the [[Pentium Pro]] and [[Pentium II]] products were announced, in the 1990s.

"Front side" refers to the external interface from the processor to the rest of the computer system, as opposed to the back side, where the [[back-side bus]] connects the cache (and potentially other CPUs).<ref name="intel">{{cite web |title= Introduction to Intel Architecture: The Basics |author= Todd Langley and Rob Kowalczyk |date= January 2009 |url= ftp://download.intel.com/design/intarch/PAPERS/321087.pdf |publisher= Intel Corporation |work= White paper |archive-url= https://web.archive.org/web/20090712091351/http://download.intel.com:80/design/intarch/papers/321087.pdf |archive-date= 2009-07-12 |url-status= dead |access-date= May 28, 2011 }}</ref>

A front-side bus (FSB) is mostly used on PC-related [[motherboard]]s (including personal computers and servers). They are seldom used in [[embedded system]]s or similar small computers. The FSB design was a performance improvement over the single [[system bus]] designs of the previous decades, but these front-side buses are sometimes referred to as the "system bus".

Front-side buses usually connect the CPU and the rest of the hardware via a [[chipset]], which Intel implemented as a [[Northbridge (computing)|northbridge]] and a [[Southbridge (computing)|southbridge]]. Other buses like the [[Peripheral Component Interconnect]] (PCI), [[Accelerated Graphics Port]] (AGP), and memory buses all connect to the chipset in order for data to flow between the connected devices. These secondary system buses usually run at speeds derived from the front-side bus clock, but are not necessarily [[Synchronization (computer science)|synchronized]] to it.

In response to [[Advanced Micro Devices|AMD]]'s [[Torrenza]] initiative, Intel opened its FSB CPU socket to third party devices.<ref>{{cite news |title= Intel opens up its front side bus to the world+dog: IDF Spring 007 Xilinx heralds the bombshell |url=  http://www.theinquirer.net/inquirer/news/1044635/intel-bus-world-dog |archive-url=  https://web.archive.org/web/20121007164914/http://www.theinquirer.net/inquirer/news/1044635/intel-bus-world-dog |url-status=  unfit |archive-date=  October 7, 2012 |author= Charlie Demerjian |date= April 17, 2007 |work= The Inquirer |access-date= May 28, 2011 }}</ref>
Prior to this announcement, made in Spring 2007 at [[Intel Developer Forum]] in Beijing, Intel had very closely guarded who had access to the FSB, only allowing Intel processors in the CPU socket. The first example was [[field-programmable gate array]] (FPGA) co-processors, a result of collaboration between Intel-[[Xilinx]]-[[Nallatech]]<ref>{{cite news |title= Nallatech Launches Early Access Program for the Industry's First FSB-FPGA Module |date= September 18, 2007 |work= Business Wire news release |publisher= Nallatech |url= http://www.businesswire.com/news/home/20070918006506/en/Nallatech-TM-Launches-Early-Access-Program-Industrys |access-date= June 14, 2011 }}</ref> and Intel-[[Altera]]-XtremeData (which shipped in 2008).<ref>{{cite news |title= XtremeData Offers Stratix III FPGA-Based Intel FSB Module |date= September 18, 2007 |work= Business Wire news release |publisher= Chip Design magazine |url= http://chipdesignmag.com/display.php?articleId=2380 |access-date= June 14, 2011 |archive-url= https://web.archive.org/web/20110723190604/http://chipdesignmag.com/display.php?articleId=2380 |archive-date= July 23, 2011 |url-status= dead }}</ref><ref>{{cite news |title= High fiber diet gives Intel 'regularity' needed to beat AMD |url= https://www.theregister.co.uk/2007/04/17/intel_idf_serverstuff/ |author=  Ashlee Vance |author-link=Ashlee Vance |date= April 17, 2007 |work= The Register |access-date= May 28, 2011 }}</ref><ref>{{cite news |title=XtremeData Begins Shipping 1066 MHz Altera Stratix III FPGA-Based Intel FSB Module |date= June 17, 2008 |work= Business Wire news release |publisher= XtremeData |url= http://www.businesswire.com/news/home/20080617005298/en/XtremeData-Begins-Shipping-1066-MHz-Altera-Stratix  |access-date= June 14, 2011 }}</ref>