I've got a Simmtronics 4GB DDR3 1333MHz PC10600U module. 2rx8 PC3-10600U-9-11-ZZ0 is written on the module. CPU-Z states CL-9, tRCD-9, tRP-10, tRas-24 and tRC-33, whereas under the SPD tab, there are values ranging from 7-33. I've got one slot free, and I plan to add another 4gb module in it. Since compatibility is a hit and trial in RAM modules, I am looking for a good module with similar specs to increase overall performance of my pc and a bit of gaming too. A bit tight on budget though. Suggestions would be highly welcome. Motherboard is Gigabyte GA-F2A55M-DS2 Rev 1.2