Ultra 4 Plus Memory Upgrade Advice Needed

beglitis wrote:
Understood. I thought maybe there was a chance that a 4GB module might actually work (despite the chipset's constraints). I really need to ask someone who knows about hardware design why does size matters in this case... (just out of curiosity)

You can download the CPU datasheet and see for yourself:

http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-d400-d500-vol-1-datasheet.pdf
http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/atom-d400-d500-vol-2-datasheet-.pdf

And actually, I'm not sure now that the thread to which I pointed you is relevant. I just re-read your original question and I see that you have the 1.5GHz Ultra 2. The CPU in that NAS is apparently an Intel Atom D405, but that part number isn't mentioned in the Intel D400/D500 Series datasheet. Therefore, I don't know if it's based on the D410 or the D425. If it's in the D425 family, the DDR3 SODIMMs recommended in that other thread should work. If it's in the D410 family, though, you'll need DDR2 memory.

Sorry I missed that the first time I read your question.

Anyway, the supported memory organization is described in Volume 1 of the datasheet on pages 9 and 27-30. As you can see, the largest memory module supported (whether DDR2 or DDR3) is 2GB. The CPUs support 4GB total, but to get 4GB you'd have to install two modules... And there's only one memory-module slot on the circuit board. (That is, there's only one slot on the Ultra 2 Plus circuit board; I guess it's conceivable that the Ultra 2 might have two slots, but I'd be very surprised.)

Again, sorry for the possibly misleading pointer to that other thread, and good luck on your upgrade.