A method and circuit arrangement utilize a low latency variable transfer network between the register files of multiple processing cores in a multi-core processor chip to support fine grained parallelism of virtual threads across multiple hardware threads. The communication of a variable over the variable transfer network may be initiated by a move from a local register in a register file of a source processing core to a variable register that is allocated to a destination hardware thread in a destination processing core, so that the destination hardware thread can then move the variable from the variable register to a local register in the destination processing core.