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CPU FSB to Memory

Last response: in Overclocking
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December 19, 2010 1:30:49 AM

I have read the AMD OC Guide and found it very useful. Especially since it applies to my CPU directly. I am just looking for some help understanding the relationship between memory and the CPU FSB. I currently have an ASUS M4A89GTD-PRO with 2x2GB G.SKill PI PC-10700/DDR1600 (6-8-6-18) and the mobo is rated for 1333 but currently have it oc'd to 1600 at the stated ratings.

1) If the bus is only 200mhz, does bumping the ram up really help?

2) And apparently only adjusting the multipliers/v is best with the x4 965?

3) What about the bandwidth with the rest of the board by adjusting the FSB?

More about : cpu fsb memory

December 19, 2010 12:40:42 PM

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 that connects the CPU to the cache. This bus and the cache connected to it are faster than
accessing the system memory (or
RAM) via the front-side bus. The bandwidth or maximum theoretical throughput of the front-
side bus is determined by the product
of the width of its data path, its clock frequency (cycles per second) and the number of data transfers it performs
per clock cycle. For example, a 64- bit (8-byte) wide FSB operating at a frequency of 100 MHz that performs 4
transfers per cycle has a bandwidth of
3200 megabytes per second (MB/s): 8 B x 1 0 0 M H z x 4 / c y c l e = 8 B x 1 0 0 M x H z x 4 / c y c l e = 8 B x 1 0 0 M x c y c l e / s x 4 / c y c l e = 3 2 0 0 M B / s The number of transfers per clock cycle is dependent on the technology used. For example, GTL+ performs 1 transfer/cycle, EV6 2 transfers/cycle,
and AGTL+ 4 transfers/cycle. Intel calls the technique of four transfers per
cycle Quad Pumping. Many manufacturers publish the speed
of the FSB in MHz, but often do not use
the actual physical clock frequency but
the theoretical effective data rate
(which is commonly called megatransfers per second or MT/s). This is because the actual speed is
determined by how many transfers
can be performed by each clock cycle
as well as by the clock frequency. For
example, if a motherboard (or
processor) has a FSB clocked at 200 MHz and performs 4 transfers per
clock cycle, the FSB is rated at 800 MT/
s.
m
0
l
December 19, 2010 12:42:24 PM

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 that connects the CPU to the cache. This bus and the cache connected to it are faster than
accessing the system memory (or
RAM) via the front-side bus. The bandwidth or maximum theoretical throughput of the front-
side bus is determined by the product
of the width of its data path, its clock frequency (cycles per second) and the number of data transfers it performs
per clock cycle. For example, a 64- bit (8-byte) wide FSB operating at a frequency of 100 MHz that performs 4
transfers per cycle has a bandwidth of
3200 megabytes per second (MB/s): 8 B x 1 0 0 M H z x 4 / c y c l e = 8 B x 1 0 0 M x H z x 4 / c y c l e = 8 B x 1 0 0 M x c y c l e / s x 4 / c y c l e = 3 2 0 0 M B / s The number of transfers per clock cycle is dependent on the technology used. For example, GTL+ performs 1 transfer/cycle, EV6 2 transfers/cycle,
and AGTL+ 4 transfers/cycle. Intel calls the technique of four transfers per
cycle Quad Pumping. Many manufacturers publish the speed
of the FSB in MHz, but often do not use
the actual physical clock frequency but
the theoretical effective data rate
(which is commonly called megatransfers per second or MT/s). This is because the actual speed is
determined by how many transfers
can be performed by each clock cycle
as well as by the clock frequency. For
example, if a motherboard (or
processor) has a FSB clocked at 200 MHz and performs 4 transfers per
clock cycle, the FSB is rated at 800 MT/
s.
m
0
l
December 19, 2010 3:17:28 PM

ok....so how does this apply only to the AMD Phenom II X4?

On CPU-Z, at the bottom of the CPU tab, I have

Core Speed = ~800MHz
Multiplier = x4 and goes as high as x17
Bus Speed = ~200MHz
HT Link = ~2000MHz

If trying to improve my system altogether, I would want to increase the bus speed right? Not just up the multiplier and look for a faster core speed?

An explanation on these characteristics and there influence on system performance might help me understand, especially on HT Link
m
0
l
!