The article shows the limits in the processing speed which
are achieved by the modern graphic cards of the NVIDIA
type. It also considers the level of the computational errors
that registered with FFT and inverse FFT at different plans for
their implementation and lack (the absence) of distortion type
jitter. A comparison of the speed of the spectral data analysis
using different plans and different drivers was carried out on
three types of graphic cards NVIDIA GeForce GTX 210,
660M, 680. Also the comparison of the speeds and the
processing errors was carried for the mentioned graphic cards
and CPU Intel Core I7. Some inconsistencies were found in
the recommended technical documentation, which is given on
the official NVIDIA website, with parameters of the really
(actually) working FFT and inverse FFT plans.