Ok, it sounds like you might not be using any SAD currently. So, yes, you'll want to use something to get a segments file before performing diarization. The SAD scripts I pointed you to earlier could help you there.
For development purposes, you might find it helpful to also use the oracle segmentation. You can get that information from the RTTM you used for scoring. That way, you can separate the sources of error (e.g., segmentation error from clustering errors).