its 1371 kh/s with 32 threads. I just checked with 18 and it produces 762 kh/s . I can see the 4 threads that don't mine from the task manager . The miner on startup shows 36 miner threads started but cpu #32, #33, #34, and #35 are missing and task manager shows only 32 online.
check the pictures below
-t 36
http://prnt.sc/eairvt-t 18
http://prnt.sc/eait62I think this a NUMA related problem. The 2 CPUs are seperated into 2 groups, which prevent the cpuminer process on CPU0 from using the memory on CPU1.
Try changing the NUMA options in your server's BIOS.