FSB and Memory Bus Speeds

[venkz]

Hi,I had a friendly argument with someone yesterday and I was sort of convinced by something that he said... but I just wanted to know if he was actually right... or was it all in the air..If I have a motherboard that has 1333 Mhz FSB and I use a DDR2 RAM of 800 Mhz, then the overall system will still be running at 800 Mhz because of the memory bus speed being at 800Mhz. And the 1333Mhz motherboard would not be a good option. Rather buying a motherboard that has an FSB of 800Mhz is a better buy...What do you guys think? Was he right. I did some googling and found that its better if we maintain the ratio at 1:1. But I'm not sure if the 1:1 they were speaking about was in the same terms... or they were speaking about something else.Any expert opinions?

 

[manu1991]

Not at all , they are independant of each other if your processor supports a 1333 Mhz FSB it will run at 1333 Mhz regardless of your RAM frequencyyour mobo will run at 800 MHz FSB ONLY IF you manually goto the BIOS and set FSB:Memory Speed as 1:1

 

[Karan]

There are two things you need to know first...

The 1333Mhz FSB and 800Mhz Memory are just their effective rates. They are actually working at ~333Mhz(quad pumped) for the processor and 400Mhz (dual rate) for the memory. The memory is faster, but the CPU uses "dividers" for that purpose.

You have to compare the actual rate and not the effective rate for the relation between the FSB and memory.

An article that explains it in detail. The Core 2's FSB, RAM and Bandwidth Explained - Icrontic.com