добавил ещё один sql server, стало лучше:

Running the test with following options:
Number of threads: 100

Doing OLTP test.
Running mixed OLTP test
Using Special distribution (12 iterations,  1 pct of values are returned in 75 pct cases)
Using "BEGIN" for starting transactions
Using auto_inc on the id column
Maximum number of requests for OLTP test is limited to 100000
Threads started!
Done.

OLTP test statistics:
    queries performed:
        read:                            1400014
        write:                           500005
        other:                           200002
        total:                           2100021
    transactions:                        100001 (2468.02 per sec.)
    deadlocks:                           0      (0.00 per sec.)
    read/write requests:                 1900019 (46892.43 per sec.)
    other operations:                    200002 (4936.05 per sec.)

Test execution summary:
    total time:                          40.5187s
    total number of events:              100001
    total time taken by event execution: 4050.0806
    per-request statistics:
         min:                                 20.94ms
         avg:                                 40.50ms
         max:                                253.15ms
         approx.  95 percentile:              51.15ms

Threads fairness:
    events (avg/stddev):           1000.0100/68.53
    execution time (avg/stddev):   40.5008/0.01