Question about FSB

[Maulin]

Is the actual FSB for a processor/motherboard, before the quad pumping/double pumping happens, always 200MHZ?
If not the why is it that most motherboard manufacturers only rate their motherboards for PC3200 RAM?
If yes then is there some body of manufactures that get togeather and decide this? and why 200MHZ why not more?

Thanks,
I prolly dont know what I am talking about, sorry if the question is stupid 😛

 

[JohnAn2112]

The stock FSB/HTT for all Intel and AMD CPU's and motherboards are 200 MHz. The standard for memory is PC3200 (DDR400) because that would be 200 MHz x 2 for Double Data Rate (DDR).

 

[Furen]

The reason why manufacturers rate their motherboards for DDR400 is because it is the highest speed DDR certified by JDEC, so it is the highest official speed. The FSB on the newer Intel CPUs is indeed 200MHz at quad data rate, but the hypertransport on the newer AMD CPUs is 1000MHz at double data rate. Hypertransport is a highspeed (ie frequency) serial link, while a traditional front-side bus is a wide, parallel link.

 

[Leper Messiah]

E rev. cores have the option of running 216, 233, and 250 memory speeds, FYI.

 

[Maulin]

Does that mean the new X2 processors also?

 

[angryswede]

Originally posted by: Furen
The reason why manufacturers rate their motherboards for DDR400 is because it is the highest speed DDR certified by JDEC, so it is the highest official speed. The FSB on the newer Intel CPUs is indeed 200MHz at quad data rate, but the hypertransport on the newer AMD CPUs is 1000MHz at double data rate. Hypertransport is a highspeed (ie frequency) serial link, while a traditional front-side bus is a wide, parallel link.

i was under the impression that both were 32 bits wide

 

[Furen]

I'm not sure about Intel's FSB width, but hypertransport (on most motherboards) is 16bits/16bits (up/down) wide. Aside from the width, Intel's FSB transfers 4 times per clock, while AMD's transfers only on the rising and falling edges of each clock (So Intel does 4x200Mtransfers per sec, while AMD does 2x1000Mtransfers).

 

[redhatlinux]

Lets not spread the myth that Intel transfers at 4 times the clock !!. Sometimes, Intel quad pumps the bus, but they also, single pump the memory bus. Absolutely, not all memory transfers are at 4 times the basic frequency.