  We consider the vacuum structure of the finite N=2 theory with N_f=2N
fundamental hypermultiplets broken to N=1 by a superpotential for the adjoint
chiral multiplet. We do this in two ways: firstly, by compactification to three
dimensions, in which case the effective superpotential is the Hamiltonian of an
integrable spin chain. In the second approach, we consider the Dijkgraaf-Vafa
holomorphic matrix model. We prove that the two approaches agree as long as the
couplings of the two theories are related in a particular way involving an
infinite series of instanton terms. The case of gauge group SU(2) with N_f=4 is
considered in greater detail.
