2 GB Limit of G4s?

[Mat]

As I follow interrested nanopicos developments and own now the MDD which got 2 x 1 GB RAM, there is another question that came to my mind. Not connected to Mac OS 9s 1,5 GB limit, but to the G4s general 2 GB limit. What is the 2 GB Ram limit about?

Did anyone ever try to put more than 2 GB in a MDD and see what happens with Linux or X? In theory every 32 Bit machine can use 4GB, so what is this 2GB-limit about? Is is some hardware issue, or did just nobody ever try it? I am asking, as the usage of 1GB rams was totally unkown to me until I opened my new MDD a few days ago and saw that it has 4 slots, two unused but already 2 GB Ram available, ...

[nanopico]

I say try it.
But it may be a limitation of the memory controller.  They are sort of dependent on how they handle banks (the size and quantity) that set the limit.

[GaryN]

It IS the limit of the memory controller. When these first came out, everybody was complaining that they had 4 slots but would only recognize 2Gb no matter how much you installed. Why? Good question…

[Protools5LEGuy]

So, the question should be:

Is there a memory controller pin-compatible with the "2 GB one" that can support more than 2?

I am talking about "swapping" memory controllers as if they weren't soldered to the MB.

[nanopico]

So, the question should be:

Is there a memory controller pin-compatible with the "2 GB one" that can support more than 2?

I am talking about "swapping" memory controllers as if they weren't soldered to the MB.

Might be kind of difficult since the memory controller integrated into the north bridge chips on the Mac's.