Performance and Memory Optimization

I observed that 100 MBs of IFC files take around 18GBs of RAM and over 1 hour and it was still reading the file no tile exported so I had to cancel the conversion. 
Is this converter performance expected?
The number of elements in the model could be around 17k to 18k, which is a normal-sized model.
Does this library make use of Parallel processing? Is there any flag to turn it on?