A configurable transactional memory synchronizes transactions from clients. The configurable transactional memory includes a memory buffer and a transactional buffer. The memory buffer includes allocation control and storage, and the allocation control is configurable to selectively allocate the storage between a transactional buffer and a data buffer for the data words. The transactional buffer stores state indicating each combination of a data word and a client for which the data word is referenced by a write access in the transaction in progress from the client. The transactional arbiter generates the completion status for the transaction in progress from each client. The completion status is either committed for no collision or aborted for a collision. A collision is an access that references a data word of the transaction from the client following a write access that references the data word of another transaction in progress from another client.