RAM Questions for Macbook.

[htg]

I'm going to upgrade my RAM in my Macbook. I know that it requires DDR2 SO DIMM 667MHz 200 pin memory, but I have a few questions:

1)When it says PC 5300, does that always mean that it's 667mhz?
2)Does it make a big difference if mix RAM from two different brands?
3)Does it make a big difference if the sizes are different (in my case, it would be a 2GB stick with a 512MB stick)?

Thanks.

 

[After G]

1. Yes, PC2-5300 = DDR2 667 MHz.
2. No it shouldn't. But there's a tiny chance they are incompatible with each other. (I had the misfortune to have this happen to me once).
3. More RAM > matching sticks.

 

[Hellhammer]

1. Yes, PC-5300 stands for 667MHz DDR2. 800MHz is called PC-6400.

2. As long as their specs are equal, it shouldn't matter

3. Dual-channeling would be disabled but that's not a big deal in real world.