  The aim of this paper is to prove a Mahler measure formula of a four-variable
Laurent polynomial whose zero locus defines a Calabi-Yau threefold. We show
that its Mahler measure is a rational linear combination of a special L-value
of the normalized newform in S_4(Gamma_0(8)) and a Riemann zeta value. This is
equivalent to a new formula for a 6F5-hypergeometric series evaluated at 1.
