I am confused by your consumer loop. Why are you changing the array to a cluster and then only looking at 8 values?
I can't run the example but it looks like you acquire 100 points but then only save 8 at a time. If you want to save the entire array I would suggest using array to spreadsheet sting rather than your cluster work there. That way you can take the entire array of data, which I assume is 100 points and save it all to file.