使用C＃在CRM 4.0中更新实体时提高性能

I have a mass update application that updates the record of a particular entity, by updating some of it's fields based on some logic. I am using TargetUpdate for the record updating because I have a workflow attached to the update of the entity which I don't want to fire (in case I use normal update). But it's taking forever to update those records. Currently it takes around 1.5 hour to update 1K records. In actual scenario, it would need to update around 10K records in a time span of 5-6 hours maximum daily(nightly job). Is there any way I can improve the performance.I have a mass update application that updates t