One of the design features which yet offers interesting margins for performance optimization ofcable-in-conduit conductors (CICCs), is their geometry. For relatively small sizeNb3Sn CICCs, operating at high electromagnetic pressure, such as those for the EDIPO project,it has been experimentally shown that a design based on a rectangular layoutwith higher aspect ratio leads to the best performance, especially in terms ofdegradation with electromagnetic loads. To extend this analysis to larger sizeNb3Sn CICCs, we manufactured and tested, in the SULTAN facility, an ITER toroidalfield (TF) cable, inserted into a thick stainless steel tube and then compactedto a high aspect ratio rectangular shape. Besides establishing a new record inNb3Sn CICC performances for ITER TF type cables, the very good test results confirmed that theconductor properties improve not only by lowering the void fraction and raising the cabletwist pitch, as already shown during the ITER TFPRO and the EDIPO test campaigns,but also by the proper optimization of the conductor shape with respect to theelectromagnetic force distribution. The sample manufacturing steps, along with the maintest results, are presented here.