RAM cards for Intel iMac 2.8Ghz versus 2.8Ghz Extreme

Question

Hi everyone,
I've just bought 4GB of RAM from Crucial to upgrade my year old iMac. Once I had placed my order I noticed that they recommended different cards for the machines with Intel 2.8GHz and 2.8GHz Extreme chips. I don't know what the difference in the memory is but they must have been different somehow as one was about $20 more expensive.
Anyway, I bought the ones for the 2.8GHz Extreme as thats what I thought I had (that's what I paid for anyway!) but I've just checked in System Profiler and there is no mention of my processor being 'Extreme' or in fact anything other than an Intel Core 2 Duo with a speed of 2.8GHz.
So my questions are:
a) Have I been ripped off by Apple and my machine isn't 'Extreme' at all - how can I tell?
b) Will the RAM I bought work on my machine whatever one it is? The RAM is certainly the correct type, i.e. number of pins etc.
Thanks for anyone that can help. If you have one of the 2.8GHz Extreme machines from last August, could you have a look in your system profiler and see if it mentions it being extreme?
Thanks again,
Neil

Answer 1

This is very easy, if you purchased your machine prior to April 2008 it is either the 2.4 or 2.8 machine. To find out for sure which one, go to the System Profiler and look under hardware you will see something very similar to this:
*Hardware Overview:*
Model Name: iMac
Model Identifier: iMac7,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.8 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 4 GB
Bus Speed: 800 MHz
Boot ROM Version: IM71.007A.B03
SMC Version: 1.21f4
Serial Number: XXXXXXXX
This is from my machine I ommitted the serial number. An even more simple way to find out is to look at the box it was shipped in, I'm assuming it is NOT a refurb model as they ship in plain brown boxes.
If you purchased your machine after April 2008 it is a little more difficult but still pretty easy. Your System Profiler will be very similar but the Bus Speed will be 1066 MHz.
The memory specification for all the mid 2007 Aluminum iMacs is the same. Use:
667 MHz, PC2-5300, DDR2 compliant (also referred to as DDR2 667) popular brands are Crucial, Kingston, OWC, etc.
If it is a early 2008 (Bus Speed 1066MHz MHz) then you will need the PC2-6400 memory chips, again all the early 2008 Aluminium iMacs use the same memory chips.