Bus/Core Ratio????

Could someone tell me what this means and what benefits I get from it? I read other places but posters keep talking about fsb and cpu multiplier but never answering what people are asking for?

Let say I want to buy a Intel T5750-667 with Bus/Core Ratio 12
and a Intel T5800-800 with Bus/Core Ratio 10

Here the link of the two comparison

Compare Intel® Products

So can anyone just make a simple reply that from the Bus/Core ratio and the fsb of 667 and 800 which one is better to have and why? Cause from looking at the specs 12 is better then 10 but I read the L305 should be able to take both the T5750 and T5800???? Read alot of posting from the net but none seems to nail it down. They are taking technical without giving any clarification to those OP questions they were asking.

 

the front-side bus (FSB) is the speed used by the CPU to communicate to the northbridge chip, which on the other hand connects to the memory modules and to the GPU (dedicated). So technically, 800MHz FSB would give better performance compared to 667MHz FSB, considering same CPU speed, though the difference could be small.

about the multipliers - this is how the CPU actually gets its speed from the clock generator.

- For the 800MHz FSB chip: the clock generator outputs 200MHz towards the CPU, thus with its internal multiplier of 10x (max) the CPU is working at 2GHz (from 10x200)
- For the 667MHz FSB chip: the clock generator outputs 166MHz towards the CPU, thus with its internal multiplier of 12x (max) the CPU is also working at 2GHz (from 12x166)

so the T5800 is slightly better than the T5750, and this is also why its code number is higher.

EDIT: when people talk about PLL pinmod overclocking, they mean raising the clock generator signal to the next available level, i.e. for example from 166 to 200MHz, thus the resulting CPU clock also rises accordingly Therefore, depending on the overclock, it might be better to get CPU with higher internal multiplier so that you can achieve higher resulting clock speed (eventually, if all works out fine).

 

Bus is referring to the bus clock (BCLK) sometimes referred to as the FSB clock.

Ratio is the multiplier used to obtain the highest frequency mode (HFM) of the CPU, not including IDA/Turbo if available. BCLK x Ratio = HFM.

Example with T5800

BCLK = 200MHz so...

HFM = (BCLK * ratio) 200 x 10 = 2000MHz

Now the confusing part.
The FSB clock is equal to BCLK, i.e. 200MHz however the clock is quad pumped (quad data rate) and can therefore transfer data at 4 times the clock speed which gives 200 x 4 = 800 Mega Transfers per Second (800MT/s). Unfortunately nearly everyman and his dog calls it MHz instead of MT/s so it's kind of stuck with being called MHz even though there is no 800MHz clock. A bit like DDR2 RAM being called 800MHz when actually the clock is 400MHz but because data is transfered twice per clock cycle (double data rate) the transfer rate is 800MT/s.

Higher FSB transfer rate results in higher bandwidth, whether it is useful will depend to some degree on how fast your RAM is.