motherboard FSB

[Martin]

Hi!

What happens if motherboard supports FSB upto 400 MHz but the processor uses just 133 Mhz FSB (Duron). Will the board use 400 Mhz for all components and 133 Mhz for the processor? Or does the board assign 133 Mhz for the whole system. Will it be possible to put 400 Mhz DDR RAM on the board? Will the board use the 400 Mhz speed for them or just 133 Mhz? Hope you understand my question....

Thanks for reply.

[Marcin]

You mean from 133 to 200 MHz effective from 266 to 400 Mhz. Result depends on motherboard and chipset. That is long long story but I will try to explain.

When you use higher FSB on CPU in same time your memory works with higher clock (higher memory bandwith in MB) and other buses works with higher clock like PCI and AGP. Some of motherboards had option in BIOS to set ratio between FSB/RAM/PCI/AGP and manual settings for memory speed.

All motherboards Socket A with nVidia nForce chipsets have locked PCI and AGP BUS speed at default speed so you setting only CPU and memory speed, timings etc.

So main question is what motherboard model you have and what settings you have in BIOS. BTW OC isn't so easy you must know all basis. Good that you ask

[*mattiz]

I am willing to buy som board that supports DDR RAM. 266 mhz, 333 or 400 mhz. I do not have enough money to buy a new processor so I am asking whether DDR 400 Mhz will run on 400 Mhz or 266 MHz. I have Duron 1.6 Ghz with 266 Mhz effective.

[Marcin]

Synchro work - will work with FSB speed so in this case 266 MHz.

Asynchro work - means will work on 400 MHz if you will choose that by manual in BIOS (if this option is available to change)

[D.8080]

DDR Ram PC3200 400 mhz will work in any ddr motherboard at the motherboard's max speed.

If you have a 333/266/200 mhz FSB mobo the ram will work at 333/266/200 mhz.

I've never seen a mobo not supporting ddr 400 so far, you'll just not use the ram at it's max speed, that's all.

[EzPcMars]

I think the question is this and Its not clear for me neither, Lets say the CPU is running at 266 mhz to my knowlege the effective clock on memory cannot be any faster then the processor itself.

I have ran benchmarks for memory and that seems to be the case, I had DDR 400 in my system but my processor is running at only 333mhz so my memory only runs at 333mhz no matter what setting I use.

So the only way to actually use you DDR400 at full speed is get a XP Processor running at 400FSB aswell.

My 10 cents, open for debate.
Marcel