core 2 duo fsb and ddr2 ram question

[dario03]

Basically I want to make sure I got this right. Now you can run a conroe with ddr2-533 but the fsb of c2d is 1066.

Now does this work because ddr2 allows you to transfer data from 2 cells instead of one so really your effective speed of ddr2-533 is 1066?

Basically 266fsb is doubled by reading on both the up and down transfer and then its doubled again by 2 chips working at the same time.


Thats right, right?

 

[Saint71]

It depend on the motherboard your using.

 

[Phrantic]

The FSB is in reality only 266Mhz but it is quadpumped (= multiplied by 4) to achieve the 1066Mhz that company marketing likes to throw at you.

Same goes for DDR2 memory. DDR2-533 really runs at 266Mhz but since it sends twice as much data in a cycle as DDR does, it has an effective speed of 533Mhz.

Meaning that with all stock settings, both the FSB base and the DRAM will run at 266Mhz.

 

[dario03]

So what I said is correct then.?.

 

[Phrantic]

No, the effective speed of DDR2-533 is not 1066. The effective speed is 533 because it's 266Mhz x 2 effectively. But you are right in your logic that it's why it runs in sync with your FSB which is 266Mhz. DDR2-533 RAM is the way to go if you don't want to overclock.

 

[b1gapl]

So if you were to get for example DDR2 1066 ram (real speed is 533 right?). It would run at DDR2 800 speeds in a motherboard which the standard is DDR2 800? And so then, you would have to overclock the ram to the speed that it is rated for.....DDR2 1066?

 

[RicoDirenzo]

NO. Your mobo may not support that 1066 RAM. It is not backward compatible in most instances.

 

[b1gapl]

I'm not talking about my mobo. I'm talking about mobos, that say their memory standard is DDR2 800.

 

[Nagasama]

i know that it will run a little faster than ddr2 800, i can get mine to boot with ram(ddr2 800) at over 500mhz (stable? PAH!), but i dont think you can get a ddr2 800 mobo to stabilize ram at 1066 speeds. alas, i don't know everything. somebody somewhere probably has.
so the answer to your question b1gapl is yes, you would have to overclock the ram to go over 800 mhz on a board that standard is ddr 800.