As a QuickBooks file starts to grow in size, transactions take longer to post into the data file.

Optimizing the QuickBooks file size will save you money in increased employee efficiency and maintain a healthy QuickBooks data file.
A QuickBooks file with more than 3 years of data can cause deterioration in performance. Large files can cause slowdowns and crashes. Also, large files can be often get corrupted easily. Though there is no limit to the file size, however, if your file size is around 150 MB, it could lead to trouble. QuickBooks starts to max out around 1GB. These large files slow down the system speed.