I have just started running STAMP (Transactional Memory benchmarks from Stanford) on Haswell. I am monitoring the TSX performance using libpfm4.4 library on Ubuntu (kernel 3.11-rc6). When I run single-threaded transactional memory benchmarks, I see transaction aborts due to data conflicts (TX_MEM.ABORT_CONFLICT) for certain benchmarks. This behavior seems strange to me considering that I am running single-threaded benchmark, so there shouldn't be any data conflicts on transactionally accessed address. Is there something that I am missing?