Na stranke DELL-u
http://www1.euro.dell.com/content/products/feature sdetails.aspx/desktop-xps-430?c=uk&
sa pise:
Up to 4GB1 1066 MHz Dual Channel DDR3 SDRAM
Four (4) user-accessible DIMM connectors, installed in pairs
S toho vyplyva maximalna velkost jedneho modulu je 1GB.

Na Tvojom odkaze ZD:
http://www.ascendtech.us/dell-xps-430-g254h-mother board_i_mbdelg254hdsimb.aspx
Memory: 4x dual-channel 1066 and 1333 -MHz DDR3 Slots, 8gb Max Total
Podla toho je maximalna velkost jedneho modulu je 2GB a maximum 8gb

No neviem, ci by som veril stranke (ascendtech), ktora udava velkost pamate v gram/bitoch (8gb).