macmini1,1 firmware can be upgraded to macmini2,1
2GB memory modules will not work in the oldest Mac Minis (2006-7),
the firmware will simply not allow the computer to start powering on if
a 2GB SODIMM is placed in the slot!
These models can be identified as:
"About This Mac -> More Info -> Model Identifier: Macmini1,1".
I have two of these old 1,1 models upgraded to Core 2 Duo processors,
which work great, but I wanted to up the memory to 3GB.
I tried some memory that should have worked to upgrade to 3GB (not 4! -see below):
http://www.amazon.com/PNY-Channel-PC2-5300-Notebook-MN4096KD2-667/dp/B000T8WN8U/ref=cm_rdp_product "PNY OPTIMA 2GB SODIMM"
it was really inexpensive- price is often $25/pair- but I sent it back... Duh!
I got some 2GB memory that was sold as definitely Macmini compatible,
and when it didn't work, I knew something was up- the firmware.
The firmware upgrade from Macmini1,1 to Macmini2,1 is a bit of a leap of faith-
not an Apple-endorsed (or even developed!) process.
But some of us leap at the chance to do hair-raising firmware upgrades
in order to wring the last bit of performance out of an old computer-
especially if it lets us use the absolute cheapest hardware!
Here is a MacRumors thread that documents the
firmware upgrade Macmini1,1 to Macmini2,1 process well:
https://forums.macrumors.com/threads/1197875/
Note- Don't let the title of this thread (Keyboard?) throw you-
it gets around to firmware, and by 2011-11-20, the process is explained in detail.
I'm hoping that someone can verify that the 2GB modules I sent back
-"PNY OPTIMA 2GB SODIMM"- really work in Mac Minis-
I believe that they MUST be used alongside a 1GB in a Mac Mini.
It is possible to upgrade an older Mac Mini with 4GB - NOT with these PNY parts -
but a little less than half of one SODIMM is wasted,
as the Core 2 Duo processor can utilize ONLY slightly more than 3GB.
I have been led to believe -and would appreciate verification- that
"Core Duo or Solo" processors (the ones that shipped with these old Mac Minis!)
can only utilize 2GB at most --even with firmware updated to Macmini2,1.
Many Mac Mini owners already have a 1GB SODIMM installed there,
so adding the cheapest 2GB SODIMM that can co-exist with the
1GB SODIMM gives the best value, and fills the memory space nearly to the top.
These PNY OPTIMA parts are listed here as a "Dual Channel Kit",
which gives a performance boost in many computers -
but the pair will NOT function AT ALL in an older Mac Mini when
both are installed in the 2 memory slots.
The results of testing Core 2 Duo Mac Minis with 2x2G vs 3GB with
several benchmarks (Photoshop, Halo, Xbench, etc.) are shown here:
http://eshop.macsales.com/shop/apple/memory/iMac_and_Mac_mini_memory_performance_testing/
Summary:
1. The firmware upgrade Macmini1,1 to Macmini2,1 process is complex and risky,
but necessary to use 2GB SODIMMS.
2. The processor in the Mac Mini may have to be a Core 2 Duo in order to
access the resulting 3GB total. (Can anyone verify?)
3. The combination of the 2GB and 1GB module is a good price/performance tradeoff,
especially as compared to adding 2x2GB modules.
4. A single "PNY OPTIMA 2GB SODIMM" from the set of 2x2GB,
when paired with a 1GB SODIMM, will operate in an older
Mac Mini computer only when the firmware is upgraded to
"Model Identifier: Macmini2,1". (Can anyone verify?)
(Reason: actually PC2-6400 SODIMM, and needs a PC2-5300 to slow it down!)