The Parallel Diagonal Dominant (PDD) algorithm is an efficient tridiag
onal solver. In this paper, a detailed study of the PDD algorithm is g
iven. First the PDD algorithm is extended to solve periodic tridiagona
l systems and its scalability is studied. Then the reduced PDD algorit
hm, which has a smaller operation count than that of the conventional
sequential algorithm for many applications, is proposed. Accuracy anal
ysis is provided for a class of tridiagonal systems, the symmetric and
skew-symmetric Toeplitz tridiagonal systems. Implementation results s
how that the analysis gives a good bound on the relative error, and th
e PDD and reduced PDD algorithms are good candidates for emerging mass
ively parallel machines.