Peter, As I mention, I can’t provide response time graph for async IO, sysbench can’t measure time for each IO in async mode.

…. To better understand response time ranges, we need to switch to synchronous IO and vary amount of threads. Throughput: And response times: We still see small hiccups in throughput and response times even for small amount of threads. For 8 threads the 95% response time is… async IO for writes. Maybe 8 threads in the first graph is too much and we should go with 1 thread…

… with normal performance the rest of time. The fact drops are relatively even all the time makes it more likely it is second case as having slowdown for longer interval of time would make dips very different depending on overlap with measurement… think it would be very interesting to plot the graph of 95% response time (which sysbench provides) for each of 10 second intervals…

… I also use Cisco UCS C250 server, and on the graph I show the results for both single card and raid… thread for random read synchronous IO: There is also excellent response time characteristics. 0.25ms and 0.19ms for 8 threads, single…

… to observe some artifacts, as you will see in following graphs. Hardware for tests: HP ProLiant DL380 G6, filesystem: ext4, mounted… internal cache or something. To understand better what kind of response time we should expect, I ran random read sync IO mode… throughput at 16-32 threads. And response time: For 16 threads, we may expect 0.96ms response time, which increases to 1.62ms under…

… to observe some artifacts, as you will see in following graphs. Hardware for tests: HP ProLiant DL380 G6, filesystem: ext4, mounted… line 222 MiB/sec To understand better what kind of response time we should expect, I ran random read sync IO mode… peak throughput at 8 threads. And response time: For 8 threads, we may expect 0.62ms response time. In general I have very good…