Is the storage limit different for different editions?

Yes, the storage limit different for different editions. Here is the information:

• Sales Starter - 5 GB or 500 MB per user
• Sales Professional - 7.5 GB or 750 MB per user
• Sales Enterprise - 15 GB or 1.5 GB per user
• Help Desk Starter - 5 GB or 500 MB per user
• Help Desk Professional - 7.5 GB or 750 MB per user
• One Professional - 15 GB or 1.5 GB per user
• One Enterprise - 15 GB or 1.5 GB per user

To know more about Storage Guard, click here.