We implemented two software transactional memory (STM) systems for Multicore OCaml from scratch and evaluated them against the production kcas library and a standard-library Mutex baseline on the GHC lab machines. We benchmarked the systems across 1 to 8 OCaml domains on four transactional data structures: a shared counter, a hash map, a linked list, and a bank account. Both STM designs trailed kcas and Mutex by a significant margin on high-contention workloads, and EP-STM exhibited substantially higher abort rates than LO-STM at moderate domain counts, but we observed relative throughput depends heavily on the read/write ratio.