I do know that Intel suggests PM45 supports 8GB, but those are rather old specs when 8GB sticks were not available. I wonder if anyone has tried 2x 8GB sticks on the VAIO? or even 2x 16GB sticks for a total of 32GB...
According to this Intel page you can only use 8GB:
And if the memory controller doesn't support more RAM, you can't use it.