def METHOD_NAME(nominal_speed, buffer_size):
    # model fitted from benchmarks from Hoodman 1000x.log - http://www.magiclantern.fm/forum/index.php?topic=5471
    # and confirmed with small tendency of underestimation on 550D SanDisk Extreme 32GB 45MBs.log
    #~ pfit = [-9.1988e-01, 6.5760e-09, 9.4763e-02, -1.1569e-04]
    # model fitted from 550D SanDisk Extreme 32GB 45MBs.log, favors smaller buffers
    #~ pfit = [-1.9838e-02, 3.0481e-09, 5.0033e-02, -5.7829e-05]
    # 5D3 movie mode, favors large buffers, http://www.magiclantern.fm/forum/index.php?topic=5471.msg38312#msg38312
    pfit = [-8.5500e-01, 4.5050e-09, 8.7998e-02, -8.5642e-05]
    speed_factor = pfit[0] + pfit[1] * buffer_size + pfit[2] * math.log(buffer_size, 2) + pfit[3] * math.sqrt(buffer_size)
    if speed_factor < 0: speed_factor = 0
    if speed_factor > 1: speed_factor = 1
    return nominal_speed * speed_factor