We developed a high-speed simulator for partial response (PR) channels employing low density parity check (LDPC) codes. Bit error rate (BER) performances for channels employing PR(1,1) and PR(1,2,2,1) targets wtih blue laser and 0.85 numerical aperture (NA) are estimated by simulating up to 10 11 data sampled which allowed us to estimate BERs as low as 10 -10 . Three data detection methods (namely, a simple slicer, soft-output Viterbi algorithm or SOVA, and maximum a posteriori probability or MAP detector) followed by LDPC decoder are compared. We also show BER performance of our one-chip hardware LDPC decoder on additive white Gaussian noise channel.