There are issues concerning the amount of power that Ram uses. Higher quality RAM uses higher density chips which use less power. From what I've read a 128meg module can come in two forms pure 128 or a kind of 64X2 arangement. This is related to the number of logical sides a module has. Each dimm slot can supply a certain amount of power. So by example I have 3 slots filled with cheap 128, in effect I am using 6 64Meg modules. So power needs to be delivered to all six.
If I had bought higher quality ram the chips would have had higher density and would be true 128. In that case I would only need to send power to 3 modules. There are numbers that describe the architecture of the chip like 64X32 but the exact specifications I don't know for each. Just something to keep an eyeout for. But there are alot of variables at play. Voltage adjust, Driving Value, Mobo power, Luck (when overclocking). Still looking for a good link to this topic. There may come a day when 512 is cheap enough or (neccessary) where alot of people would want to max out board specifications. Just from looking around it is rare to see anyone with problems at a total of 512 in any arrangement, but I've seen posts describing problems with 384 Megs. This really isn't alot of help. Sorry. Common sense would say a dual board would handle the power requirements better. The antithesis is that the dual board is a converted single, and therefore would have more demands placed on it. Ow, this hurts me noggin'