Occurrences of both transient and permanent errors pose a major challenge in the wake of burgeoning growth in transistor density. Manufacturing defects and process variants lead to permanent faults, thereby lowering processor yields. In the arithmetic logic unit, single permanent faults result in the absolute failure of processors. Both low-energy neutrons and alpha particles from the cosmos induce transient errors by altering the state of the transistor. In wake of the implications, we postulate a new, reliable, fault-tolerant, low-cost 32-bit one instruction core (OIC) for a multicore system. “Low cost” here means low power and lower area. Notably, 32-bit OIC provides fault-free execution with triple redundant subtractors with one additional subtractor. It only executes one instruction called subleq repetitively in order to emulate the faulty instructions migrated into it by other cores. Hardware synthesis is undertaken to estimate leakage power, dynamic power, critical path delay, and area. The low-power 32-bit OIC consumes 1.3 mW, with a die area of 8,122 μm2. Apart from also adding performance overhead, 32-bit OIC outperforms its competitors with regard to reliability, area, power, and critical path delay. Additionally, the probabilistic estimate with link vulnerability factor—as a new parameter—is introduced to assess the effect of soft errors or transient faults on interconnect wires, which are then quantitatively analyzed to illuminate the resilience of 32-bit OIC hardware structure. Additionally, we propose new design alternatives (including existing ones) for heterogeneous multicore systems in order to develop low-cost solutions with a primary focus on reliability. © 2019 ASTM International. All rights reserved.