Dropped frames still can't be solved

I have a GigE Vision camera with resolution 2048*2048 and the highest frame rate is 20.I follow the instructions from the following website.It really reduce the frequency of the error occurrence - "gige: Block/frame 313 is being dropped because a lost packet is unable to be resent........." but the problem still can't be truly solved.

http://www.mathworks.com/matlabcentral/answers/91834-how-do-i-calculate-the-packet-delay-for-a-gige-vision-camera-to-prevent-dropped-frames

my simplified code is following:

vid=videoinput('gige',1, 'BayerGR8'); src = getselectedsource(vid); src.PacketSize = 9000; delay = CalculatePacketDelay(vid,src.AcquisitionFrameRate); src.PacketDelay = delay; triggerconfig(vid,'mannual'); start(vid); for i = 1:10000000 a = getsnapshot(vid); end stop(vid);