Actaully, having 1 stick is better then having 2. When you have two they each have to transfer between each other actaully giving you slightly slower speed, its not noticible but it is slower.
That .. doesn't really make sense.
Copying from RAM to RAM is not done by the memory or the memory controller itself, but (usually) by the CPU (if that is necessary, as determined by the application you run). It's one read operation, and one write operation. It does not matter where you write to.
you can mix and match DDR chips from what I know they will just clock down to the lowest common denominator.. ie the slowest DDR chip or the Motherboard if its controller is slow..
With the latest boards, you can, they are usually smart enough to pay attention to the voltage and clock requirements of all components you stick in - unless you manually set a faster clock speed or different voltages, that is. Never recommended, unless you know what you are doing.
General note on Dual Channel Technology:
- your board needs to support it (almost all P4 boards do)
- With the exception of one special nForce chipset, you can only use dual channel with an even number of modules.
- pairs of modules need to have the same size
- all modules must have the same clock speed.
- all modules must have the same "layout" (single sided vs. double sided, plus the same number of chips on them)
So, just buy two identical ones.
