Macbook 1,1 RAM upgrade

Hello everybody,
I'm hoping that you guys will be able to me. I'm trying to figure out what kind of RAM my computer can upgrade with (I want 2 GBs cos that's the highest my computer can upgrade). My boyfriend is insisting that I can use this: Corsair Apple 2048MB PC5400 DDR2 667MHz SODIMM Memory at TigerDirect.com

My specs are as follows:
Model Name: MacBook
Model Identifier: MacBook1,1
Processor Name: Intel Core Duo
Processor Speed: 2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per processor): 2 MB
Memory: 768 MB
Bus Speed: 667 MHz

I've looked around at other forums and I noticed that everybody is throwing 2 sticks of RAM into their computers. My boyfriend doesn't think that this is necessary and just says 1 will do. Is this true and why or why not? I also noticed that the RAM he chose (see the link above) says PC5400. The RAM I currently am using is PC2-5300. Is there a difference because they both say DDR2 and what is this difference? Thanks in advance for your help.

Your boyfriend showed you the wrong type of memory. For starters, you need two 1GB sticks, not a single 2GB stick. PC2 5400 should be fine, but you should stick with PC2 5300 just to avoid any possible problems.

Here's what you need: G.Skill 2GB (2x1GB)

While your machine will run just fine on 1GB of memory, you really should upgrade to 2GB. The difference is very noticeable, especially if you run a lot of programs at once. I too started with 1GB on my machine and soon upgraded to 2GB, and then I maxed out my machine at 3GB. Each upgrade was totally worth it. I'm actually thinking of upgrading my desktop from 4GB to 8GB.

Thanks, I'll let him know!