[Observium] Flush process causing slow performace

Since upgrading PHP to 5.4, Observium has loaded very slowly at times. Most of the time just a refresh of the homepage will take .150 seconds but occasionally it can take up to a minute to load. Running iotop shows the Flush process running taking up 99.99% IO which directly correlates to the slow page loads. Can anyone shed some light on a way to resolve this?