Jan 27 2008, 02:43 AM, updated 18y ago
QUOTE
In personal computers, the front side bus (FSB) or system bus is the physical bi-directional bus that carries all electronic signal information between the central processing unit (CPU) and the northbridge.
Some computers also have a back side bus which connects the CPU to a memory cache. This bus and the cache memory connected to it are faster than accessing the system RAM via the front side bus.
The maximum theoretical bandwidth of the front side bus is determined by the product of its width, its clock frequency and the number of data transfers it performs per clock tick. For example, a 32-bit (4-byte) wide FSB with a frequency of 100 MHz that performs 4 transfers/tick has a maximum bandwidth of 1600 megabytes per second (MB/s). The number of transfers per tick is dependent on the technology used, with (for example) GTL+ offering 2 transfers/tick, EV6 4 transfers/tick, and AGTL+ 8 transfers/tick.
Notice that many manufacturers give the speed of the FSB in megatransfers per second (MT/s), and not in megahertz (MHz). The MT/s is affected by how many ticks are performed for each MHz, so if a motherboard has a 266 MHz FSB and performs 4 transfers per clock tick, it has a total data transfer rate of 1066 MT/s. That is what the manufacturers give as the speed of the FSB. Intel calls this technique which has 4 ticks per cycle Quad Pumping.
Some computers also have a back side bus which connects the CPU to a memory cache. This bus and the cache memory connected to it are faster than accessing the system RAM via the front side bus.
The maximum theoretical bandwidth of the front side bus is determined by the product of its width, its clock frequency and the number of data transfers it performs per clock tick. For example, a 32-bit (4-byte) wide FSB with a frequency of 100 MHz that performs 4 transfers/tick has a maximum bandwidth of 1600 megabytes per second (MB/s). The number of transfers per tick is dependent on the technology used, with (for example) GTL+ offering 2 transfers/tick, EV6 4 transfers/tick, and AGTL+ 8 transfers/tick.
Notice that many manufacturers give the speed of the FSB in megatransfers per second (MT/s), and not in megahertz (MHz). The MT/s is affected by how many ticks are performed for each MHz, so if a motherboard has a 266 MHz FSB and performs 4 transfers per clock tick, it has a total data transfer rate of 1066 MT/s. That is what the manufacturers give as the speed of the FSB. Intel calls this technique which has 4 ticks per cycle Quad Pumping.
So, the FSB is actually a very inefficient bus system for the CPU to communicate with the rams and other parts of the PC. So lets take a look how much a bottleneck that the fsb does to the rams.
Test System:
Intel C2D E6750
Patriot Value rams 1gb x2
P35 DS3
Benchmark Used:
SuperPi XS 1.5, 2M calculations
Lavalys Everest cache and memory benchmark v4.10.1120 beta
Sisoft Sandra Engineer 2007.6.11.42
Windows XP 32bit SP3
This post has been edited by bryanyeo87: Jan 27 2008, 03:33 AM
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dont get parts u dont need and only get what u need 
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