You need to do some performance tuning. It's not about log files, it's about the time the query takes to run. Identify the problematic queries and see if you can tune them.
Oh, and about that log file, please read through this - Managing Transaction Logs[/url]
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability