increasing the number of threads results on a result of 0.0 MiB/s

[flixman]

Running this command sysbench --memory-block-size=2G --memory-total-size=20G --threads=16 memory run I am getting this result:

sysbench 1.0.20 (using system LuaJIT 2.1.1720049189)

Running the test with following options:
Number of threads: 16
Initializing random number generator from current time


Running memory speed test with the following options:
  block size: 2097152KiB
  total size: 20480MiB
  operation: write
  scope: global

Initializing worker threads...

Threads started!

Total operations: 0 (    0.00 per second)

0.00 MiB transferred (0.00 MiB/sec)


General statistics:
    total time:                          0.0008s
    total number of events:              0

Latency (ms):
         min:                                    0.00
         avg:                                    0.00
         max:                                    0.00
         95th percentile:                        0.00
         sum:                                    0.00

Threads fairness:
    events (avg/stddev):           0.0000/0.00
    execution time (avg/stddev):   0.0000/0.00

However, if I set it to 8 threads, I get the following:

sysbench 1.0.20 (using system LuaJIT 2.1.1720049189)

Running the test with following options:
Number of threads: 8
Initializing random number generator from current time


Running memory speed test with the following options:
  block size: 2097152KiB
  total size: 20480MiB
  operation: write
  scope: global

Initializing worker threads...

Threads started!

Total operations: 8 (   14.50 per second)

16384.00 MiB transferred (29697.41 MiB/sec)


General statistics:
    total time:                          0.5501s
    total number of events:              8

Latency (ms):
         min:                                  339.89
         avg:                                  455.80
         max:                                  549.95
         95th percentile:                      549.52
         sum:                                 3646.36

Threads fairness:
    events (avg/stddev):           1.0000/0.00
    execution time (avg/stddev):   0.4558/0.07