did you try without the ram yet? im sure that holds your oc back quite a bit
get rid of that 5300 RAM, and just go with 2x1GB, at least for the sake of 3dmark. AMD chips don't like to have all the slots filled 'cause it puts more stress on the memory controller, which is on the CPU, which is why having all 4 slots occupied can hinder an ovderclock. Also, with all 4 slots filled, AMD motherboards like to default to 2T timings, also possibly slowing things down.