I. C90/T90/T914 Comparisons

• GAMESS statistics
  • C90/T94 ratio over 35 jobs is 1.54
  • C90/T914 ratio over 34 jobs is 1.36
  • T90/T914 ratio over 44 jobs is 1.13

• GAUSSIAN94 statistics
  • C90/T914 ratio over 17 jobs is 1.27

  The following very small set are much longer jobs, which tend to get much better performance than the set above which has a majority of fairly small runs. In a couple of the job types, the T90 is seen to be actually 'unreasonably' better in performance, and this must be due to the optimizations that GAUSSIAN INC. was responsible for with regard to the T94 platform, which we then took over to the T90 platform.

  • C90/T94 ratio 1.56
  • C90/T914 ratio 1.5

• CADPAC statistics
  • C90/T914 ratio over 9 jobs is 0.8

II. The following is a compilation of data for a benchmark that has been consistently run over the years on the various hardware that we have had come in. The table shows ratios of timings for various combinations of hardware.

Hardware Performance Comparisons:

Platform	Ratio
T3D/T3E		6.0
T3E/SP2		1.8
Origin/SP2	1.0
Paragon/SP2	15.0
AlphaFarm/SP2	5.0
T3E(64node)/C90	3.0
IBM595/C90	3.0
C90/T90		1.5

III.The following are some direct comparisons between GAMESS and GAUSSIAN for various types of jobs:

JOB 1: tetragonal SiH5- with 6-311++G(d,p)

platform      application   SCF           SCF+GRAD      HESSIAN       MP2           
c90                                                                                 
              GAMESS        11            23            146           41            
              G94           11            19            131           16            
rs6000/350                                                                          
              GAMESS        25            45            665           90            
              G94           60            95            474           103           

JOB 2: Long bond isomer of tetrasilabicyclobutane with 6-31G(d,p)

platform      application   SCF           SCF+GRAD      HESSIAN       MP2           
c90                                                                                 
              GAMESS        66            158           1384          136           
              G94           22            44            636           53            
rs6000/350                                                                          
              GAMESS        140           306           3985          224           
              G94           169           303           2580          607