MBP RAM issue

[BigMac77]

I recently installed 2x2GB RAM sticks in my MBP. The "About this Mac" window shows I have 4GB of RAM. However, activity monitor only shows 3. What the hell?

 

[Michael CM1]

I recently installed 2x2GB RAM sticks in my MBP. The "About this Mac" window shows I have 4GB of RAM. However, activity monitor only shows 3. What the hell?

I know some of the older MBPs will only actually use 3GB. I don't know at what point that changed. I know that my 2.16Ghz that I bought 13 months ago only uses 3. I know that the latest ones can use 4.

 

[BigMac77]

I guess that's the problem. I have the same MacBook Pro. Still weird though, the "About this Mac" tab shows 4GB. Do you think that I would be better off using a 2GB and a 1GB? Would it run better one way or the other?

 

[Mashiach]

About this mac is most likely registering that you have 4gb in the slots as it is reading that specific size. With activity monitor it is usually only concerned with things that the system is using and as it looks like you have the old gen. MBP this will be why it is telling you that you have 3gb of RAM as you can only access that amount.

 

[Bobioden]

Any release before June of '07 can only support 3GB of Ram.

 

[CanadaRAM]

I guess that's the problem. I have the same MacBook Pro. Still weird though, the "About this Mac" tab shows 4GB. Do you think that I would be better off using a 2GB and a 1GB? Would it run better one way or the other?

You will be slightly faster (6% or so) with the pair of 2 GB SODIMMs, as the machine is able to use dual channel memory access -- compared with a 2 GB and a 1 GB SODIMM.