A7N8X Memory Question

I am looking to purchase this board soon (or an equivalent). The board states it can run an FSB of 333/266/200.

The processor will probably be an Athlon XP running a 266Mhz FSB.

The RAM portion says it can handle Dual Channel DDR400. We can forget about the dual channel for now as I don't know enough about it yet.

Ok, the board and CPU are running in-sync at 266Mhz.

If DDR400 RAM is running at effectively 200Mhz, how does the RAM keep up? Is this right?

Or is the CPU and board effectively saying that those speeds are DDR already (making the FSB and CPU actually 133Mhz). In that case, wouldn't most fo the current RAM then be running too fast?

I am so confused with all the new stuff (current system is a nice little 133Mhz FSB with Athlon 1Ghz and 1 stick of 512 PC133).

Your cpu would be running at 266Mhz (133x2) and your ram would be running at 400Mhz (200x2) if you select to run it by Spd. However if you choose to overclock your cpu (lower multiplier and increase bus) to maximize on memory bus then this would be best. Try to run ram and cpu a-sync.

Hope this help somewhat not too good at explaining this stuff.

if you run the ram at 266 then it isn't running at 400.

If you find memory capable of running 400 then you can't run it in sync with your 266 CPU.

By the way the actual numbers you'll probably see are 133, since 266 isn't really describing anything. DDR266 is usually called PC2100 (based on it's memory bandwidth, which is at least meaningful. "DDR266" is really "PC133 but since it makes 2 operations per cycle I decided to double the number, which used to be how many cycles but now it's how many clock-cycles and PC133 is 133mHz only multiplied by 1 (sorry I suddenly became passionate).

In any case, with PC2100 you'll set your fsb for 133. nForce2 mobos can run the memory up to 200 mhz for an effective DDR400 (clock-cycles). They also don't run well out of sync so you'd really need to OC your CPU fsb to 200mhz also.

There's where I lose track. Can you set an nForce2 mobo to CPU fsb of over 133 or is it impossible? If not that means you can't overclock 333mhz CPUs with them. Please keep in mind that modern CPUs also run internally at double the fsb clock speed so at 133fsb your CPU runs at 266 and fsb of 166 will mean your CPU is running 332 internally (but 333 is more catchy!) as the newest CPUs are designed for.