Did you have a look at client tracing?
It should give you an overview where TSM spends its time.

"traceflag instr_client_detail" in the options file should give you
something
like

Final Detailed Instrumentation statistics
Elapsed time: 144.568 sec
Section Total Time(sec) Average Time(msec) Frequency used
------------------------------------------------------------------
Client Setup      0.180              180.0              1
Process Dirs     51.495               56.1            918
Solve Tree        0.000                0.0              1
Compute           0.501                0.0          23558
Transaction      21.398                0.3          80602
BeginTxn Verb     0.000                0.0             36
File I/O         96.640                3.0          32496
Compression       0.000                0.0              0
Encryption        0.000                0.0              0
CRC               0.000                0.0              0
Delta             0.000                0.0              0
Data Verb        11.813                0.5          23558
Confirm Verb      0.000                0.0              0
EndTxn Verb      13.595              377.6             36
------------------------------------------------------------------

Thomas Rupp