text: -- Get CPU Utilization History for last 30 minutes (SQL 2008)
  DECLARE @ts_now bigint = (SELECT cpu_ticks/(cpu_ticks/ms_ticks)FROM sys.dm_os_sys_info); 
  
  SELECT TOP(30) SQLProcessUtilization AS [SQL Server Process CPU Utilization], 
                 SystemIdle AS [System Idle Process], 
                 100 - SystemIdle - SQLProcessUtilization AS [Other Process CPU Utilization], 
                 DATEADD(ms, -1 * (@ts_now - [timestamp]), GETDATE()) AS [Event Time] 
  FROM ( 
  	  SELECT record.value('(./Record/@id)[1]', 'int') AS record_id, 
  			record.value('(./Record/SchedulerMonitorEvent/SystemHealth/SystemIdle)[1]', 'int') 
  			AS [SystemIdle], 
  			record.value('(./Record/SchedulerMonitorEvent/SystemHealth/ProcessUtilization)[1]', 
  			'int') 
  			AS [SQLProcessUtilization], [timestamp] 
  	  FROM ( 
  			SELECT [timestamp], CONVERT(xml, record) AS [record] 
  			FROM sys.dm_os_ring_buffers 
  			WHERE ring_buffer_type = N'RING_BUFFER_SCHEDULER_MONITOR' 
  			AND record LIKE '%<SystemHealth>%') AS x 
  	  ) AS y 
  ORDER BY record_id DESC;