Hi Jing, Could you also provide the corresponding performance/IOPs data? This will help narrow down if the problem is truly performance related, or a reporting problem in the perf tool. If you wouldn't moving this to an issue in the SPDK GitHub tracker, we can make sure it gets tracked as well. http://github.com/spdk/spdk/issues Thanks, -Jim On 2/12/19, 2:53 PM, "SPDK on behalf of Jing Liu" < spdk-bounces(a)lists.01.org on behalf of jingliu.cs(a)gmail.com&gt; wrote: Hi, I'm doing simple benchmark on spdk NVMe Driver, but get some surprising bad result. Queue Depth 1 2 4 8 16 32 64 128 256 average-latency AIO (us) 59.72 59.48 60.99 65.26 74.53 93.8 137.83 239.74 473.74 SPDK (us) 57.39 57.21 59.36 64.66 77.3 104.58 182.12 364.33 729.95 I'm using the perf tool in example/nvme/perf/ for both aio and spdk nvme driver. *** # ./perf /dev/nvme0n1 -L -q $QD -s 4096 -w randread -t 600 > aio_QD${QD}.log *** # ./perf -L -q ${QD} -s 4096 -w randread -r 'trtype:PCIe traddr:0000:01:00.0' -t 600 *** before the benchmark I pre-condition the SSD using # /dev/nvme0n1 -q 32 -s 131072 -w write -t 1200 SPDK version: 18.04.1 Hardware I'm using: Samsung 970 Pro, 1TB NVMe SSD. It seems spdk cannot scale well with Queue Depth based on my result. Am I missing something? Thanks, Jing _______________________________________________ SPDK mailing list SPDK(a)lists.01.org https://lists.01.org/mailman/listinfo/spdk _______________________________________________ SPDK mailing list SPDK(a)lists.01.org https://lists.01.org/mailman/listinfo/spdk