  We study large N orbifold equivalences involving three-dimensional N=3 and
N=4 supersymmetric quiver Chern-Simons-matter theories. The gravity dual of the
N=3 Chern-Simons-matter theory is described by AdS4xM7 where the tri-Sasaki
manifold M7 is known as the Eschenburg space. We find evidence that a large N
orbifold equivalence for the N=4 case continues from the M-theory limit to the
weak-coupling limit. For the N=3 case, we find consistent large N equivalences
involving a projection changing the nodes of the gauge groups, and also for a
projection changing Chern-Simons levels where for the latter projection, the
BPS monopole operators behave as expected in large N equivalence. For both
cases we show, using the gravity dual, that the critical temperature of the
confinement/deconfinement transition does not change and the entropy behaves as
expected under the orbifold equivalence. We show that large N orbifold
equivalence changing Chern-Simons levels can be explained using the planar
equivalence in the mirror dual.
