| The HARMONi will work with any DIMM that works with the "stock" iMac (rev. A - D), supporting total memory up to 512MB.
There are some 256MB modules that can only be utilized as 128MB, due to a limitation of the parts used at the time that these iMacs were manufactured. A controller chip used in the system's design can recognize a maximum of 128MB of RAM in each "bank" of memory. Until recently, virtually alll 256MB DIMMs used two banks of 128MB. Recent advances in RAM have led to the introduction of some DIMMs with 256MB in a single bank, which has raised the visibility of this issue. These parts are stable, and are not known to reduce system reliability, but they will not deliver the full desired memory capacity. There is no single method for identifying these parts without installing them, so it is recommended that you work with a reseller who can either confirm the design, or who will accept a return based on compatibility. |