The emergency of hardware transactional memory (HTM) has greatly boosted the transaction processing throughput in in-memory databases. However, the group commit used in in-memory databases, which aims at reducing the impact from slow persistent storage, leads to high transaction commit latency. Non-volatile memory (NVM) opens opportunities for reducing transaction commit latency. However, HTM cannot cooperate with NVM together: flushing data to NVM will always cause HTM to abort. This study proposes a technique called Parity Version to decouple the process of HTM execution and NVM write. Thus, the transactions can correctly and efficiently use NVM to reduce their commit latency with HTM. This technique has been integrated to DBX, a state-of-the-art HTM-based database, and DBXN: A low-latency and high-throughput in-memory transaction processing system, is proposed. Evaluations using typical OLTP workloads, including TPC-C, show that it has 99% lower latency and 2.1 times higher throughput than DBX.