When installing more than one DIMM, it is recommended to get the same type of memory (same size, same speed, same manufacturer) for each slot.
Applied Models: TS-453Bmini, TS-x53A, TS-x51A, TS-x51, TS-253 Pro, TS-453 Pro, TS-453mini, TS-653 Pro, TS-853 Pro, TS-451U, TS-x53U, TS-563, TS-x63U, TVS-x63, IS-453S, TBS-453A, TS-251+, TS-451+, TS-963X