You sure you got DDR3 .. I have 2 e5 v4 rigs at home and both have ddr4 ... Unless I am wrong and 2011-3 supports ddr3 and ddr4
The first two generations supported DDR3 only. Haswell and Broadwell (v4) brought DDR4 support.
The first two generations supported DDR3 only. Haswell and Broadwell (v4) brought DDR4 support.