text: SELECT TOP 10
  [Wait type] = wait_type,
  [Wait time (s)] = wait_time_ms / 1000,
  [% waiting] = CONVERT(DECIMAL(12,2), wait_time_ms * 100.0 
               / SUM(wait_time_ms) OVER())
  FROM sys.dm_os_wait_stats
  WHERE wait_type NOT LIKE '%SLEEP%' 
  ORDER BY wait_time_ms DESC;
  
  -- http://msdn.microsoft.com/ru-ru/library/ms179984.aspx - расшифровка задержек на MSDN