The overall imaging rate depends on the execution times of three major processes: signal acquisition; data transfer time from PC host memory to the GPU (Table 1, col. 3); and processing and visualization time (Table 1, col. 4). In the most time-effective situation the data acquisition rate should match the rate of the processing and visualization. In such a case, frame rate would depend on the transfer time (Table 1, col. 3) and processing time (Table 1, col. 4), and the overall frame rate would be given by the numbers in Table 1, col. 6. However, at the present level of the development of the technology, data acquisition is slower than data processing, and new data are rarely available for the processing software. Therefore, the same data set can be processed and displayed several times with frame rates given in Table 1, col. 5. This feature is used in our software for online adjustments of data processing (e.g., dispersion compensation) and display parameters (e.g., rotation angle, zoom). When the numerical analysis is taken into account (without transfers) the processing rate on GPU is about 800,000 spectra (2048 points each) per second for structural examination and 550,000 spectra per second in the case of Doppler OCT analysis (Fig. 2).