CPU-to-RAM speed question

[Tymetwister]

With a Intel Celeron 2.0Ghz/400 FSB processor, and a board with a DDR Standard of PC3200 (DDR400), can I get a true 400Mhz speed out of my memory?

 

[Nitestick]

you will NEVER get a true 400mhz out of memory unless it is DDR2. DDR400 is actually 200mhz. so if you can set the FSB of the processor at 200mhz then it will run at DDR400

 

[Tymetwister]

The FSB on the processor is 400Mhz, so shouldn't that work?

If not... how do I increase the FSB speed?

 

[Nitestick]

that is not the actual FSB, that is an Intel marketing gimmick. i don't know what the actual FSB on that cpu is but take my word for it that it is not 400mhz. take say one of the "800mhz" FSB Pentium 4's. they actually have a 200mhz FSB which is "quad pumped" to give 800mhz

 

[Brtnboarder495]

Yup, Intel's typical "FSB" is 200mhz just like AMD's "HTT" is 200mhz.

Note that FSB and HTT are basically the same thing, it's just that the two companies use different names for them.

But this year AMD is moving to a HTT of 333mhz with their Socket AM2 CPU's, as Intel is as well.

Intel already had a 1066mhz FSB (266mhz effective) on some of their EE Socket T/Socket LGA 775 CPU's though, but their also upping theirs to 1333mhz (333mhz effective) on some of their EE Conroe processors.

 

[reggie_da_man]

On a system like that the ram will be downclocked to 100MHz to match the Celeron's system bus, not the FSB.

 

[idiotec]

The Celly FSB is quad pumped as well, so the true FSB is 100Mhz (100x4 = 400). If the board has native support for DDR400, then it may have a divider setting for the RAM to run faster than the FSB (2:1 - RAM:FSB).

 

[Tymetwister]

Also, if it won't work, then what's the minimum requirement processor I need for it to run at the correct speed of PC3200? (Motherboard socket is 478)

 

[Apokalipse]

Note that FSB and HTT are basically the same thing, it's just that the two companies use different names for them.

not really. AMD's HTT is only on K8 processors, and it refers to the communication speed between CPU and RAM directly

the FSB is used by Intel and by older AMD CPU's, and is the communication speed between the CPU and the motherboard's memory controller. the memory controller on systems with a FSB then acts as the bridge between CPU and RAM

 

[reggie_da_man]

Also, if it won't work, then what's the minimum requirement processor I need for it to run at the correct speed of PC3200? (Motherboard socket is 478)

You would need a CPU with an FSB of 800MHz or system bus of 200MHz.