I am seeing little bit difference in the page response time in sandbox and production org's. Actually, i am thinking the production org instance is faster than the sandbox instance because it might be running on powerful servers. Is that true?
According to this article from 2013, Sandboxes are configured with a 4 node clustered database tier while Production have an 8 node clustered database tier.
While that may have changed since publication, I would guess they do have more powerful servers running production.
In some situations sandbox and production can perform similarly, but SOQL query performance can vary greatly due to the following factors:
Different hardware configurations Differences in data skew Data fragmentation in production (as opposed to contiguous data in sandbox as a result of the sandbox copy process) Different usage patterns Differences in the presence of custom indexes and skinny tables All of these contribute to differences in run time. In a lot of cases, SOQL queries in sandbox can have a lower run time, and you may often find customers are frustrated because SOQL queries - particularly queries in Batch Apex start() methods - execute fine in sandbox but time out in production.
The two main contributors to query performance differences are contiguous tables created during the sandbox copy process, and resources competing for cache.