We consider matrix theory compactified on T-3 and show that it correct
ly describes the properties of Schwarzschild black holes in 7 + 1 dime
nsions, including the mass-entropy relation, the Hawking temperature,
and the physical size, up to numerical factors of order unity. The mos
t economical description involves setting the cutoff N in the discreti
zed light-cone quantization to be of order the black hole entropy. A c
rucial ingredient necessary for our work is the recently proposed equa
tion of state for 3 + 1 dimensional supersymmetric Yang-Mills theory w
ith 16 supercharges. We give detailed arguments for the range of valid
ity of this equation following the methods of Horowitz and Polchinski.