Doppler ultrasound for quantifying blood and tissue motion is angle-dependent and has maximum detectable velocity limitation. Speckle tracking, on the other hand, can be utilized to estimate velocity vectors. The combination of high frame-rate imaging and speckle tracking has the potential to achieve accurate motion estimation but the computation requirement may be a concern. It is the purpose of this study to assess performance of the combination of high frame-rate data acquisition and speckle tracking, called high frame-rate speckle tracking. Main factors under investigation include image signal-to-noise ratio (SNR) and velocity gradients. Two sets of experiments and one set of simulations of bulk motion and flow motion were conducted to evaluate the influences of the factors mentioned above. The results show that high accuracy can be achieved under sufficiently high SNRs. In addition, computational complexity of high frame-rate speckle tracking is acceptable due to the smaller search range resulting from the relative smaller displacement under high frame rate imaging.