Confused about memory restrictions on GA-P31-DS3L motherboard

I'm about to build a system based on an Intel E6750 processor and a
GA-P31-DS3L motherboard. I currently have two 1Gb sticks of Corsair
TWIN2X2048-6400 RAM to go in it. I'm also considering installing the 64-bit
version of Vista Home Premium, in which case I will purchase a further two
sticks of the aforementioned memory. However, I'm puzzled by a couple of
statements in the motherboard's specs.

The first is :

"Because of chipset limitations, do not populate both DIMM sockets of the
same channel (e.g. DDRII1 and DDRII2), or populate 4 DIMM sockets with
double-sided memory modules to prevent system's failure to start or
incorrect detection of memory modules."

The second is:

"Because of chipset limitations, when using FSB 1333 MHz CPU with populating
all DIMM sockets, memory frequency will be reduced from the original, and
system instability or incorrect detection of memory module may be occur."

I'm probably being thick here, but I can't quite work out the ramifications
of this. Does it mean that although Gigabyte have provided four memory slots
they can't all be used simultaneously? Also, if I do populate all of them
with the memory mentioned above, what can I expect to happen in practice?

Any and all ideas gratefully received.

Steve Silverman

Basically the P31 chip does not support the 1333 FSB natively. Gigabyte and others make it do this through overclocking. However, when you OC the FSB on this chipset, it drains the memory voltage. Double sided memory modules draw more voltage(1.9-2.4v) than single sided(1.8v).

If you were to use four sticks of say, Corsair Value ram(single sided), you should be OK. However, if you load it up with 4 sticks of XMS(double sided), then you are likely to have memory stability problems due to the voltage draw. This is why the MB bumps everything down to 1066 FSB(266 base).

It is actually a bit more involved than this, but that is the simplest explanation I can come up with.

To sum up, the optimum config for that MB would be a 1066 or 1333 FSB processor with 4x1gb sticks of DDR2 667 or 800 "value ram".

The best config for the XMS ram would be the P35-DS3L MB.

Although the manual does not say specifically, the approved memory list does have some 2gb modules listed from Geil and Micron, so I would say yes. However, you are still limited to 4gb total(either 4x1gb, or 2x2gb).

Yes.