Carification Request: xw8400 and xw8600 DIMM Requirements

[DBrunnenmeyer]

From the xw8400's QuickSpecs document:

"Use only fully-buffered, PC2-5300F DIMMS (FB-DIMMs). Match DIMMs by size and type. With the exception of the single-DIMM
configuration, all memory should be added in like pairs."

The three sentences above could be interpreted two ways.   (1)  All DIMMs must be identical in size and type, e.g.  8 each 2GB for a total of 16GB but not 4 each 2GB with 4 each 1GB for a total of 12GB.  (2) A different configuration (12GB) would be OK if the DIMMs are added in like pairs that are matched in type and size..

The examples in the QuickSpecs favor the first configuration above but the disclaimer says that not all configurations are illustrated. Which interpretation is correct? The first one, where ALL modules must be identical?

[DGroves · Accepted solution]

you know HP does post the FULL service manual online for the xw8400 that goes into details on each subject that the 2 page quickspec pamphlet can not cover (which is why it's called "quickspec")

i'm not sure why the sentence disclaimer says that not all possible configurations are illustrated. is giving you fits, there was limited space in the printed manual for illustrations,  and showing every possible memory configuration's pictures would be a waste of space

if you read the manual part FULLY on memory you will know that EACH MEMORY BANK must be filled  with the same size /frequency module ,......IE-BANKS OF TWO, going from smallest memory size to largest.

the memory layout is also posted on the xw8400's removable side door

From the xw8400 service manual:

-------------------------------------

You must load memory modules in valid configurations:

• If loading only one DIMM, install it in slot 1. Otherwise, DIMMs must be loaded as matched pairs.
• If loading two DIMMs, install them in slots 1 and 3.
• If loading four DIMMs, install them in slots 1, 3, 5, and 7.
• If loading six DIMMs, install them in slots 1 through 5, and 7.
• If loading eight DIMMs, install them in all slots.
• Load the memory module pairs in order of size, from smallest to largest.