FSB speed ? (confused)

[mechoption]

Here's my specs:

MoBo: ASUS P4P800 (http://www.asus.com/products/mb/socket478/p4p800/overview.htm)
Chip: P4 2.4 GHz with C1 core (no HT)
Memory: 4 sticks of 256MB PC2700 (Set up to dual page)
Video: ATI Radeon 9600 Pro
Power: 400W something or other.

Now, when I run Cpu-z or PC-Wizard 2004 I get told that my FSB speed is 133MHz ?? Is that right? My Mother board is rated at 800MHz (although I've never seen RAM that fast?) and the PC2700 DDR SDRAM is 333MHz, so, to the best of my knowledge my FSB should be 333MHz ?? Or am I getting something terribly wrong here?

PS: I'm fairly new to this so let me know if my reasoning is wrong.

Cheers,
Mech.

 

[Rambo]

Well, theoretically, your CPU's FSB can only be equal to or above your RAM's FSB. I have never known of it working the other way round...Not sure why it is giving you that information...

But yes, you are right, your RAM's FSB can't be above your CPU's.

 

[tweaker]

I get told that my FSB speed is 133MHz?? Is that right?

It's quad pumped, (133 x 4 ~ 533Mhz fsb)

My Mother board is rated at 800MHz (although I've never seen RAM that fast?)

Newer S478 procs runs with 800Mhz fsb (quad 200 x 4).
PC3200 is the minimum to be used with them.

 

[mechoption]

ahh, so my FSB is defined by the CPU Bus speed. So even if I dropped in 4*400MHz SDRAM, presumably my FSB would remain at 133MHz? Does anyone know a good site that explains this 'quad pumping' ? You lost me at 'q'

Thanks for the info !

 

[tweaker]

ahh, so my FSB is defined by the CPU Bus speed.

Your fsb (front side bus) is your cpu's bus speed.

So even if I dropped in 4*400MHz SDRAM, presumably my FSB would remain at 133MHz?

Yes.

Does anyone know a good site that explains this 'quad pumping' ? You lost me at 'q'

The Quad pumped P4 transfers four bits of data over each bus line every clock tick.

 

[mechoption]

Hazzah I think I understand now (maybe). So, even if I upgraded to PC3200 (same size) presumably I wouldn't see any system improvement as I'm only asking each RAM chip to run at 133MHz and therefore the PC3200 RAM would be underused? (as is my PC2700 right now).

Is this logic right?

 

[Praetor]

Well, theoretically, your CPU's FSB can only be equal to or above your RAM's FSB. I have never known of it working the other way round...Not sure why it is giving you that information...

You can have ram clocks higher than core clocks

So, even if I upgraded to PC3200 (same size) presumably I wouldn't see any system improvement as I'm only asking each RAM chip to run at 133MHz and therefore the PC3200 RAM would be underused? (as is my PC2700 right now).

Well 133MHz = PC2100. 166MHz = PC2700