Continuous saving to STEP file

Hi,
I convert my model data to STEP file through STEPCAFControl_Writer. Here is code:

Handle(TDocStd_Document) aDoc;
Handle(XCAFApp_Application) anApp=XCAFApp_Application::GetApplication();
anApp->NewDocument("MDTV-XCAF",aDoc);
Handle(XCAFDoc_ShapeTool) myShapeTool=XCAFDoc_DocumentTool::ShapeTool(aDoc->Main());
Handle(XCAFDoc_ColorTool) myColors=XCAFDoc_DocumentTool::ColorTool(aDoc->Main());

for(Standard_Integer i=1; i TDF_Label aLabel = myShapeTool->NewShape();
myShapeTool->SetShape(aLabel, sequenceOfShapes.Value(i));
}

STEPCAFControl_Writer myWriter;
myWriter.Perform(aDoc, fname);

The problem is large allocating of memory (sample STEP output had about 120MB and memory during conversion was about 1.1GB). I would ask if it is possible to save the STEP file continually so that the memory was released during conversion. E.g. by this way: I have data divided to sequence of TopoDS_Compound. Would it be possible to write one compound, release its memory, write next compound, release its memory and so on?

Thanks.