4 GB in iMac?

Josias

macrumors 68000
Original poster
Mar 10, 2006
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Since the new iMacs support 1x1 GB + 1x2 GB SO-DIMM's, would it be possible to put in 4 GB RAM (2x2 GB), or do you think Apple made a firmware lock as on the MBP's?
 

robbieduncan

Moderator emeritus
Jul 24, 2002
24,638
61
Harrogate
If they supported 4Gb RAM I think Apple would happily sell you it. As they do not offer this option I don't think it'll work.
 

ipacmm

macrumors 65816
Jun 17, 2003
1,304
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Cincinnati, OH
^ I agree, it might work but then again I would guess would love to tell everyone the iMac's support up to 4GB over 3GB's if they did.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
57
Wait until the developer note comes out -- it may shed some more light on things.

But as some people have noted, with the way the Intel chipset sets up the hardware DMA -- that some of the memory space may be used by the hardware.

Not noticed until you try to stuff 4GB in there and only see slightly over 3GB for memory.

At least the new CPU gets the consumer machines past 2GB.

And the next chipset should hopefully be 8GB for 2 DIMMs.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
57
I guess this answers it sort of ... seems the DMA and hardware addresses probably suck up the rest. Basically the same as the Windows users saw with the chipset.
iMac (Late 2006): Memory Specifications

Note: If you do install a 2 GB SO-DIMM in both the bottom and top memory slots of the computer, the About This Mac window and Apple System Profiler will both show that you have 4 GB of SDRAM installed. However, Activity Monitor and other similar applications will reveal that only 3 GB of SDRAM has been addressed for use by the computer.
 

Josias

macrumors 68000
Original poster
Mar 10, 2006
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Sun Baked said:
I guess this answers it sort of ... seems the DMA and hardware addresses probably suck up the rest. Basically the same as the Windows users saw with the chipset.
Oh okay. 3 GB in a consumer machine is crazy anyway. And getting 2 GB is so cheap now.:D
 

Nutter

macrumors 6502
Mar 31, 2005
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London, England
The odd thing is that the iMac developer note states that "additional RAM must be installed in pairs of equal sizes."

I'm confused. How is 3GB possible in that case?
 

Josias

macrumors 68000
Original poster
Mar 10, 2006
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Nutter said:
The odd thing is that the iMac developer note states that "additional RAM must be installed in pairs of equal sizes."

I'm confused. How is 3GB possible in that case?
Because Apple are magic magicians!:p

nah, I guess that is just recommended to get dual channel ability. Just like it is possible to get 256 MB + 1 GB in MacBook's, it should be possible to get 1 + 2 GB in ye iMac.;)