No more than 3 Gb RAM?

[Habberkuk]

Hi, I have the 17" 2006 iMac 2.0 GHz Core 2 Duo. I know that the processor is 64 bit, but it won't use more than 3.25 GB which is the max that 32 bit will support ... why ? It would be nice to upgrade the RAM to 4 GB from the 3 GB that is currently installed.
The operating system is 10.6.8

Any help is appreciated

 

[macthefork]

According to OWC, it should take 4GB RAM.

 

[jav6454]

Remember, integrated graphics reserve memory automatically, which means, even though you might install 4GB, you won't have all 4GB at your usage.

 

[Habberkuk]

According to OWC, it should take 4GB RAM.

It will take 4 GBs, but only 3.25 will be addressed...

Remember, integrated graphics reserve memory automatically, which means, even though you might install 4GB, you won't have all 4GB at your usage.

It doesn't have an integrated GFX card, it has the ATI Radeon X1600 with 128 MB VRAM

But thanks for both replies

 

[macthefork]

How are you determining that your iMac is only able to access 3.25 GB of RAM?

If you look at "About This Mac" it will show you the amount of accessible RAM (total usable RAM). If you look in Activity Monitor, under System Memory, it will show you the Free RAM not used by your OS or other currently running programs.

Are you saying that under "About This Mac" is only showing 3.25 GB when 4 GB is installed?

 

[crazzyeddie]

Those models can only address 3.3GB of RAM due to a motherboard limitation. There's nothing you can do about that, unfortunately.

 

[benwiggy]

Are you saying that under "About This Mac" is only showing 3.25 GB when 4 GB is installed?

Yes. I had one of these Macs. You can add 4Gb, but only 3Gb will be addressed.
http://www.everymac.com/systems/apple/imac/faq_cd/imac-intel-how-to-upgrade-memory.html
As said, it's a limitation of the motherboard, nothing to do with the CPU's 64-bit-ness itself.

 

[Habberkuk]

Well... It seems like it won't be able to adress 4 GB...
But anyway, thank you for helping