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Legacy

macrumors 6502
Original poster
Jul 27, 2005
353
0
London
Ok tecchies I am getting hugely confused by the information I find on the net!
I am about to get an iMac DV model (400Mhz G3, Tangerine, Firewire Slot Loading) and I want to upgrade the memory.

I know that they support 168pin as oppose to previous 144pin, but I have been reading that these iMacs do not recognise PC133 memory, and only take PC100.

Also, what is the difference between Mac/PC memory in this context and would I need to differentiate between the two when making my purchase?

Could someone please clarify this for me?

Thank You
 

CanadaRAM

macrumors G5
Legacy said:
Ok tecchies I am getting hugely confused by the information I find on the net!
I am about to get an iMac DV model (400Mhz G3, Tangerine, Firewire Slot Loading) and I want to upgrade the memory.
I know that they support 168pin as oppose to previous 144pin, but I have been reading that these iMacs do not recognise PC133 memory, and only take PC100.
Also, what is the difference between Mac/PC memory in this context and would I need to differentiate between the two when making my purchase?
Could someone please clarify this for me?
The biggest issue you will run into is that they don't support high density modules. Most PC133 generic memory is built with high density chips, so that a 512 Mb DIMM will have 8 or even just 4 chips on it. The G4 Macs need a 512 Mb module with 16 low density chips on it (or a 256 Mb module with 8 low density chips). PC133 is fine as long as the module is not locked at 133 MHz - the SPDs have to be written so that it can run at both 100 and 133 MHz.

Still your best bet is to buy from a reputable seller who guarantees compatibility.
 

Legacy

macrumors 6502
Original poster
Jul 27, 2005
353
0
London
CanadaRAM said:
The biggest issue you will run into is that they don't support high density modules. Most PC133 generic memory is built with high density chips, so that a 512 Mb DIMM will have 8 or even just 4 chips on it. The G4 Macs need a 512 Mb module with 16 low density chips on it (or a 256 Mb module with 8 low density chips). PC133 is fine as long as the module is not locked at 133 MHz - the SPDs have to be written so that it can run at both 100 and 133 MHz.

Still your best bet is to buy from a reputable seller who guarantees compatibility.

http://www.crucial.com/uk/store/lis...=Apple&tabid=AM&model=iMac+(G3-400)&submit=Go

from this information:

SDRAM, PC133 • CL=2 • Unbuffered • Non-parity • 133MHz • 3.3V • 64Meg x 64

So if I find a chip that satisfies these criteria, would it be correct to assume that it is compatible with the iMac?

Regards
 

CanadaRAM

macrumors G5
Legacy said:
http://www.crucial.com/uk/store/lis...=Apple&tabid=AM&model=iMac+(G3-400)&submit=Go

from this information:

SDRAM, PC133 • CL=2 • Unbuffered • Non-parity • 133MHz • 3.3V • 64Meg x 64

So if I find a chip that satisfies these criteria, would it be correct to assume that it is compatible with the iMac?

Regards
It has to

1) be made of low density chips
2) have SPD settings that permit operation at 100 MHz.

The spec doesn't tell you that.

So it would not be safe to assume.
 

Legacy

macrumors 6502
Original poster
Jul 27, 2005
353
0
London
CanadaRAM said:
It has to

1) be made of low density chips
2) have SPD settings that permit operation at 100 MHz.

The spec doesn't tell you that.

So it would not be safe to assume.

Thanks, I guess I will have to ask the seller then..cheers for your assistance!
 
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