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I’m using a Core Duo MacBook White (not core 2 duo) for a while and have it upgraded to the maximum 2 GB of RAM. What happens if I just put two 2GB RAM modules in there?

Has anyone experience “over-upgrading” the MacBook RAM?

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up vote 1 down vote accepted

I don't know about your particular model, but if the max is 2 GB of RAM, your machine will only ever see/use 2 GB of RAM. It will most likely ignore the other 2 GB of RAM.

However, if your max is two 1 GB RAM modules, that may possibly mean that each RAM slot can only support 1 GB of RAM each, meaning that two 2 GB RAM modules wouldn't work at all. Hard to tell.

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It's very likely that the machine won't even boot if you put 2x2 in there. The motherboard will probably throw a POST error when you try. – BBlake Feb 3 '10 at 15:50
Right, it most likely will not post at all. – th3dude Feb 3 '10 at 16:09
I reckon I'll find a friend with a DDR25300 2GB dimm to just give it a go. Have a suspicion that it'll just not start. – kevin Feb 5 '10 at 13:00

While this is already answered, I wanted to add my own experience from decades of using Computers.not just Macs, but old-school Atari 8-bit machines, PCs, Solaris servers, etc…

The reality is there is pretty much no way to know how a machine will react nor even understand how it will stably react when limits on user upgradable parts are pushed. Meaning, let’s say the theoretical 2 GB of RAM still shows up even if you toss 4 GB of RAM in there. There is no way to know if that 2 GB of available RAM will react stably under load. The system will report 2 GB of RAM available, but the second you launch a process that maxes that RAM out? You might just get a kernel panic from the logic board not knowing how to properly handle the RAM.

This also applies to data storage such as hard disks: Toss a 3 TB drive into an enclosure that is rated to only handle 2 TB and you have 100% no clue what might happen. You might get 2 TB of storage reported. I recently saw only 840 GB (?!?) of storage reported when I did this. And then, even if you accept the reported limit, no telling what will actually happen when your data is on that drive.

In general, you cannot “over clock” RAM or data storage. You need to play within the recommended limits. And heck, if some enterprising retailer that does repairs somehow discovers you can install more RAM or storage that officially specced? Well go for it! I trust retailers who do their own R&D work to push the limits of systems because they have an economic investment to not only prove their upgrades can push the limits, but also prove such an upgrade is stable. Otherwise, why purchase anything from them>

But unless you have a machine, time & energy to spare, best play within designated boundaries. Any perceived benefit you might get “squeezing” more out of your machine could be instantly lost from a systems failure.

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