An apparatus and method for redundant transient fault detection. In one embodiment, the method includes the replication of an application into two communicating threads, a leading thread and a trailing thread. The trailing thread may repeat computations performed by the leading thread to detect transient faults, referred to herein as “soft errors.” A first in, first out (FIFO) buffer of shared memory is reserved for passing data between the leading thread and the trailing thread. The FIFO buffer may include a buffer head variable to write data to the FIFO buffer and a buffer tail variable to read data from the FIFO buffer. In one embodiment, data passing between the leading thread data buffering is restricted according to a data unit size and thread synchronization between a leading thread and the trailing thread is limited to buffer overflow/underflow detection. Other embodiments are described and claimed.