Making a geoshow map with many mat files having large number of rows

I have total 92 number of matfiles having more tham 600000 number of rows for each matfiles. Column number 7 and 8 are the latitude and longitude for the files. I want to make a geoshow map using the lat and longs of all the files. As these are large files, I am facing the problem. Please help. I am using 2017a version.