I found an interesting article about the logging timer jobs in SharePoint 2010.
http://msdn.microsoft.com/en-us/library/gg512103.aspx#bk_splog
In this article, it is stating that all the following timer jobs are disabled by default.
Timer jobs:
Diagnostic Data Provider: Event Log (Collects Windows Event Log entries and stores the data in the logging database.
10 minutes)Diagnostic Data Provider: Performance Counters - Database Servers (Collects Performance Monitor Counters data on database servers and stores the data in the logging database. 5 minutes Important: The timer service account must have sufficient permission to collect counters on the database server. The account should be a member of the Performance Monitor Users (PMU) group.)
Diagnostic Data Provider: Performance Counters - Web Front Ends (Collects Performance Monitor Counters data on front-end Web servers and stores the data in the logging database.
5 minutes)Diagnostic Data Provider: SQL Blocking Queries Diagnostic Data (Collects data associated with blocked SQL queries and stores the data in the logging database. 15 seconds)
Provider: SQL DMV Diagnostic Data Provider: SQL Memory DMV Diagnostic (Collects SQL Dynamic Management Views (DMV) data and stores the data in the logging database. 30 minutes)
Data Provider: Trace Log (Collects Trace Log entries and stores the usage data in the logging database and stores the data in the logging database. 10 minutes)
My question is now: Is it a performance problem to activate all these timer jobs?