This document indicates the max DIMM the Dell R610 can accept is 8GB:
http://support.dell.com/support/edocs/systems/per610/en/HOM/pdf/hom_en.pdf
(page 116)
This document says it can accept DIMMs up to 16GB:
www.dell.com/downloads/.../server-poweredge-r610-specs-en.pdf
(page 2)
So is it 96GB or 192GB? Maybe a BIOS reflash is needed to get it up to 192GB?