Comment by lolcw

No they don’t. Models ending in 6 have DDR3 controller.

For example

E5-2696 v3/v4 E5-2686 v3/v4 E5-2666 v3/v4

also

2673 v3/v4 2678 v3/v4

as well as E5 2629 v3 E5 2649 v3 E5 2669 v3