Table-A) CPU performance: 10.5.r04(rrr) vs. 10.5.r06 (aka 10.6.beta)
Legend:
10.5.r04rr  = geant4-10-05-ref-04(re-build and re-run, as of May 29, 2019)
10.5.r04rrr = geant4-10-05-ref-04*re-build and re-run as of June 28, 2019) 

Average (CPU Time)/Event: 10.5.r04rr  vs 10.5.r04rrr
#----------------------------------------------------------------------------
#  105r04rr                105r04rrr             100*(r04rrr-r04rr)/r04rr  sample
#
#  mean      error         mean      error       %diff error
#----------------------------------------------------------------------------
  268.3800   2.7948 	  269.3900   3.1275 	   0.4  1.6	 higgs.FTFP_BERT.1400.4 
   15.0560   0.1045 	   15.2050   0.1148 	   1.0  1.0	 e-100MeV.FTFP_BERT.100MeV.4 
   31.3660   0.1726 	   31.6920   0.2409 	   1.0  0.9	 e-100MeV.Shielding.100MeV.4 
   91.6930   0.6173 	   93.4140   0.6680 	   1.9  1.0	 e-100MeV.Shielding_EMZ.100MeV.4 
    0.0140   0.0001 	    0.0139   0.0001 	  -0.7  1.0	 e-.FTFP_BERT.1.0 
    0.0699   0.0004 	    0.0696   0.0005 	  -0.4  0.9	 e-.FTFP_BERT.5.0 
    0.1404   0.0008 	    0.1394   0.0009 	  -0.7  0.9	 e-.FTFP_BERT.10.0 
    0.6958   0.0055 	    0.6904   0.0053 	  -0.8  1.1	 e-.FTFP_BERT.50.0 
    0.0179   0.0001 	    0.0180   0.0001 	   0.6  0.8	 e-.FTFP_BERT.1.4 
    0.0899   0.0006 	    0.0906   0.0007 	   0.8  1.0	 e-.FTFP_BERT.5.4 
    0.1796   0.0011 	    0.1812   0.0012 	   0.9  0.9	 e-.FTFP_BERT.10.4 
    0.8915   0.0060 	    0.8986   0.0064 	   0.8  1.0	 e-.FTFP_BERT.50.4 
    0.0248   0.0001 	    0.0248   0.0002 	   0.0  0.9	 pi-.FTFP_BERT.1.0 
    0.1019   0.0007 	    0.1018   0.0006 	  -0.1  0.9	 pi-.FTFP_BERT.5.0 
    0.1905   0.0012 	    0.1900   0.0010 	  -0.3  0.8	 pi-.FTFP_BERT.10.0 
    0.8724   0.0056 	    0.8678   0.0060 	  -0.5  0.9	 pi-.FTFP_BERT.50.0 
    0.0279   0.0001 	    0.0280   0.0002 	   0.4  0.8	 pi-.FTFP_BERT.1.4 
    0.1152   0.0006 	    0.1153   0.0007 	   0.1  0.8	 pi-.FTFP_BERT.5.4 
    0.2206   0.0011 	    0.2207   0.0014 	   0.0  0.8	 pi-.FTFP_BERT.10.4 
    1.0300   0.0063 	    1.0366   0.0074 	   0.6  0.9	 pi-.FTFP_BERT.50.4 
    0.0281   0.0002 	    0.0280   0.0002 	  -0.4  1.0	 pi-.QGSP_BERT.1.4 
    0.1158   0.0007 	    0.1154   0.0006 	  -0.3  0.8	 pi-.QGSP_BERT.5.4 
    0.2217   0.0013 	    0.2214   0.0011 	  -0.1  0.8	 pi-.QGSP_BERT.10.4 
    1.0254   0.0066 	    1.0286   0.0073 	   0.3  1.0	 pi-.QGSP_BERT.50.4 
    0.0275   0.0001 	    0.0275   0.0001 	   0.0  0.5	 pi-.QGSP_BIC.1.4 
    0.1166   0.0005 	    0.1164   0.0005 	  -0.2  0.6	 pi-.QGSP_BIC.5.4 
    0.2216   0.0010 	    0.2214   0.0014 	  -0.1  0.8	 pi-.QGSP_BIC.10.4 
    1.0373   0.0062 	    1.0392   0.0069 	   0.2  0.9	 pi-.QGSP_BIC.50.4 
    0.0647   0.0003 	    0.0650   0.0004 	   0.5  0.8	 anti_proton.FTFP_BERT.1.4 
    0.1531   0.0008 	    0.1531   0.0008 	   0.0  0.7	 anti_proton.FTFP_BERT.5.4 
    0.2595   0.0015 	    0.2602   0.0015 	   0.3  0.8	 anti_proton.FTFP_BERT.10.4 
    1.0804   0.0057 	    1.0834   0.0074 	   0.3  0.9	 anti_proton.FTFP_BERT.50.4 
    0.0187   0.0001 	    0.0187   0.0001 	   0.0  0.8	 proton.FTFP_BERT.1.4 
    0.1112   0.0006 	    0.1114   0.0006 	   0.2  0.8	 proton.FTFP_BERT.5.4 
    0.2217   0.0010 	    0.2218   0.0013 	   0.0  0.7	 proton.FTFP_BERT.10.4 
    1.0482   0.0063 	    1.0509   0.0064 	   0.3  0.9	 proton.FTFP_BERT.50.4 
    0.1180   0.0004 	    0.1167   0.0008 	  -1.1  0.8	 pi-.FTFP_INCLXX.1.4 
    0.4008   0.0017 	    0.3977   0.0023 	  -0.8  0.7	 pi-.FTFP_INCLXX.5.4 
    0.7249   0.0027 	    0.7206   0.0042 	  -0.6  0.7	 pi-.FTFP_INCLXX.10.4 
    1.0414   0.0047 	    1.0341   0.0060 	  -0.7  0.7	 pi-.FTFP_INCLXX.15.4 
    0.0939   0.0005 	    0.0930   0.0006 	  -1.0  0.8	 proton.FTFP_INCLXX.1.4 
    0.4540   0.0020 	    0.4514   0.0028 	  -0.6  0.8	 proton.FTFP_INCLXX.5.4 
    0.8341   0.0035 	    0.8245   0.0052 	  -1.2  0.7	 proton.FTFP_INCLXX.10.4 
    1.1713   0.0059 	    1.1562   0.0072 	  -1.3  0.8	 proton.FTFP_INCLXX.15.4 
    0.1428   0.0006 	    0.1437   0.0008 	   0.6  0.7	 proton.FTFP_BERT_HP.1.4 
    0.7419   0.0025 	    0.7468   0.0026 	   0.7  0.5	 proton.FTFP_BERT_HP.5.4 
    0.1554   0.0010 	    0.1571   0.0011 	   1.1  1.0	 proton.Shielding.1.4 
    0.8374   0.0057 	    0.8451   0.0046 	   0.9  0.9	 proton.Shielding.5.4 
    0.1426   0.0006 	    0.1416   0.0008 	  -0.7  0.7	 gamma.FTFP_BERT_EMZ_AugerOff.250MeV.0 
    0.2060   0.0012 	    0.2045   0.0013 	  -0.7  0.9	 gamma.FTFP_BERT_EMZ_AugerOn.250MeV.0 
    0.0562   0.0004 	    0.0558   0.0003 	  -0.7  0.9	 gamma.FTFP_BERT_EMZ_AugerOff.1.0 
    0.0812   0.0005 	    0.0805   0.0005 	  -0.9  0.9	 gamma.FTFP_BERT_EMZ_AugerOn.1.0