I write custom reports for Sage 100 Contractor, lots of them, for clients around the USA.

PROBLEM: Some reports are complicated, but run quickly at some clients, and the same report very slowly at another.

• Quick like 40 seconds,
• slow like 25 minutes,
• Same Report. 
• Running the report in the database of a company 2x the size of the slow company, but it runs in 2.18 minutes, 24 minutes at the slow company.

QUESTION: What could be causing the slow running at the slow company? Structural setup of their system? ANY IDEAS?  Thanks.