Um ein grundlegende Informationen eines SQL Servers unter Last/Stress zu erhalten nutze ich typischerweise diese Performance Counter welche Microsoft standardmaßig bereit stellt.

Performance Non-Disk Counters

Object Counter
Memory Available Mbytes
Memory Pages Input/Sec
Memory Pages/Sec
Paging File %Usage
Paging File %Usage Peak
Process (sqlservr) %Processor Time
Process (Processes) %Processor Time
Processor %Privileged Time
Processor %Processor Time
System Processor Queue Length

Performance Disk Counters

When the data files are places on a SAN additionally Use the performance
tools provided by the SAN vendor + SQLIO tool!

Object Counter
PhysicalDisk Avg. Disk Sec/Read   
PhysicalDisk Avg. Disk sec/Write

Performance SQL Server Counters

Object Counter
SQL Server Buffer Manager: Buffer cache hit ratio
SQL Server Buffer Manager: Page life expectancy
SQL Server SQL Statistics: Batch Requests/Sec
SQL Server SQL Statistics: SQL Compilations/Sec
SQL Server SQL Statistics: SQL Re-Compilations/Sec
SQL Server General Statistics: User Connections
SQL Server Locks: Lock Waits / Sec: _Total
SQL Server Access Methods: Page Splits / Sec
SQL Server General Statistic: Processes Block
SQL Server Buffer Manager: Checkpoint Pages / Sec