pegatron corporation 2ab6

I'd like to upgrade my graphics, so I'd like to know what would be the best option Pegatron Corporation 2AB6 has a DDR3 slot and PCIE 2.0 x 16 I've seen people talking about using GTX 660 but I checked this one is DDR5, how could be this possible? I was considering to use a ZOTAC GT 730 4GB...

How can I find an update for my Pegatron Corporation 2AB6 motherboard? I got a HP Pavilion P7-1080LA, and I have a problem with my RAM slots, I can only use two slots, and I can't use dual channel! I mean, I need to use 2 slots together (a blue and a black), and if I use two blue or two black...