[Pw_forum] geometry optimizaion-how to make it faster

[Sen]

Dear all,
         As I am trying to get the optimized geometry of an 192-atom
system,my parallel-run gets slower as the total force reads the
following:
 Total force =   194.872598     Total SCF correction =     0.008989
 Total force =   186.362843     Total SCF correction =     0.007976
 Total force =   184.690859     Total SCF correction =     0.004865
 Total force =   179.229678     Total SCF correction =     0.005298
 Total force =   173.830737     Total SCF correction =     0.005438
 Though the run still continues, I fear, it would take months to reach
something like "End of BFGS Geometry Optimization". I am using the
following  input (briefly given):
&CONTROL
  calculation  = "relax",
  restart_mode = 'from_scratch',
  prefix       = "nanomol",
  pseudo_dir   = "/work1/asen/pwscf/newwork1/pseudo",
  outdir       = "/work1/asen/tmp",
/
&SYSTEM
  ibrav = 6,
  celldm(1) = 22.0,
  celldm(3) = 3.8,
  nat       = 192,
  ntyp      = 4,
  ecutwfc = 25.0,
  ecutrho = 200.0,
  occupations='smearing',
  smearing='Gaussian broadening',
  degauss=0.01,
/
&ELECTRONS
  diagonalization='cg',
  conv_thr    = 1.0e-6,
  mixing_beta = 0.1,
/
&IONS
  pot_extrapolation = "second_order",
  wfc_extrapolation = "second_order",
--------
Au  18.601360 16.000000   0.000000
Au  18.601360 16.000000  54.570496
---------------
--------------
Au  15.451947 13.457026  81.183342
-----------
Au  17.718653 14.047231  80.089668
-------------
--------------
S   15.998219 14.326591  31.279226
C   16.001303 16.565260  33.968327
H   17.675220 17.770269  33.820061
H   14.330640 17.774763  33.819920
---------------
The atomic positions are okay, however, the individual atom forcee are
coming like this:
     atom   1 type  1   force =     8.78530224    1.13988509  -14.03979912
     atom   2 type  1   force =    12.01091279    1.31202407  -13.48731135
     atom   3 type  1   force =     9.69708845   11.26363626   -5.68058137
     atom   4 type  1   force =     9.72514514   11.34982112   -4.79680588
     atom   5 type  1   force =    -2.54144525    8.89141511  -13.86762764
     atom   6 type  1   force =    -3.12157312   11.70097423  -12.31860197
     atom   7 type  1   force =    10.21942251    9.52077429   -0.85911975
     atom   8 type  1   force =     9.81543682    9.46159249   -0.73870247
     atom   9 type  1   force =    -1.32878929   12.88147452    2.62586847
     atom  10 type  1   force =    -1.32982873   14.40215166    1.69396997
     atom  11 type  1   force =   -13.51902374    6.88366314   -5.08150330
     atom  12 type  1   force =   -13.53147027    6.74037823   -5.25299321
----and so on.
I would greatly appreciate your valuable suggestions on what would be the
most effecive way in handling such situations.
Best regards,
Sen