I have a X58-USB3 Gigabyte main board. Previously, I had 3*4 Patriot 2000 but I needed more memory so added 3*4 Corsair 2000 sticks. (I couldn't find the same brand). To install the memory sticks, I put 3 Patriot sticks on (2,4,6) slots and 3 Corsair sticks on (1,3,5) slots. After increasing memory I think the speed of my computer decreased.
Is the ordering of the memory modules important?