Conversion of Characteristic Values to SIDs taking Long time

Hello experts,

I know this has been discussed many times on the forum but not finding the suitable solution for my scenario.

I have a flow like DS -> DSO (SID Generatio During Activation checked) -> Cube.

Till yesterday my DTP was taking 17 mins to load 900K records & today suddenly it's taking more than 2 hrs to complete the same DTP with average same no of records.

Cube is set to full delete (without dimension table content) & reload.

I have checked Report SAP_INFOCUBE DESIGNS & two dimensions among the cube are 300% of the FACT table !! But has been from the past one year & not sure why DTP has started taking long time from today itself..

Harshawardhan.