In this paper, we investigate the performance of the spatial-temporal zero-forcing linear equalizer architectures for a single-carrier Massive MIMO uplink system under frequency-selective fading environment. We establish relationships between the choosing equalizer length $D$ and the system performance in terms of system degrees of freedom and signal-to-interference plus noise ratio (SINR). We also present how system parameters (number of antennas $M$ and the transmit signal-to-noise ratio) impact the system performance differently for both single-cell systems and multi-cell systems with perfect and imperfect channel state information. Furthermore, we show that the probability density function (PDF) of the SINR can be accurately approximated as a Gamma distribution by using the moment matching method. Then, closed-form expressions of the ergodic rate and the outage probability are derived based on the PDF of the SINR.