Check point comes slow

Hi, We are facing slow checkpoint issue as statistics given bellow. In the bellow statistics check points taking time ,as 5 transactions that blocked waiting for in one checkpoint and 21 in other. we also observed that during check point slow response its taking time to give connection to application, but during investigating the message log file we found no error or advisory related to check point but response is slow.While earlier it was working fine. Critical Sections Physical Log Logical Log Clock Total Flush Block # Ckpt Wait Long # Dirty Dskflu Total Avg Total Avg Interval Time Trigger Time Time Time Waits Time Time Time Buffers /Sec Pages /Sec Pages /Sec 66191 08:23:45 CKPTINTVL 18.8 9.4 0.0 5 2.8 6.8 9.4 18 1 10 0 146 0 66192 08:29:38 CKPTINTVL 42.9 9.6 0.0 21 6.9 20.8 34.7 24 2 16 0 90 0 Can you please give us the root cause of this slow check point occurrence? or how we can investigate the actual reason due to which its comes slow? Regards, Khurram Shahzad