1. This
work
was
performed
as
a
part
of
the
Performance
Analysis
Workgroup
and
the
Discipline
Specific
User
Support
for
Chemistry
project
within
NOTUR.
1

2. Our
system,
a
very
successful
choice
of
name
–
a
bit
too
successful.
2

3. To
those
of
you
not
familiar
with
Gaussian.
3

4. 56
atoms
Semi-­‐aromaOc
TransiOon
metal
Closed
electronic
shell
For
this
study,
we
used
a
rather
typical
problem
set
–
a
molecule
represenOng
a
typical
job
type
(geometry
opOmizaOon
using
DFT)
and
a
medium
sized
problem
(56
atoms,
one
transiOon
metal,
closed
electronic
shell
molecule).
4

5. In
the
Stallo
system
each
blade
enclosure
contains
one
Ethernet
and
one
Infiniband
switch
connecOng
the
16
nodes
within
the
enclosure
with
each
other.
The
Ethernet
switch
only
have
one
1
gigabit/second
uplink
shared
by
the
16
nodes
in
the
enclosure,
therefore
all
benchmarks
were
performed
within
one
blade
enclosure
to
prevent
arOficial
performance
differences
when
comparing
Ethernet
and
Infiniband
runs.
5

6. 6

7. 7

8. 8

9. 9

10. 10

11. We
also
exploit
the
specific
naming
of
“LindaWorkers”
in
the
Gaussian
output
for
IP
over
IB
and
IB
using
Rsockets
to
do
this
trick.
Acknowledgements:
Sean
Hedy,
INTEL
Corp,
implementor
of
the
Rsockets
library.
Roy
Dragseth,
UiT,
who
came
up
with
this
idea
and
implemented
it.
11

12. 12

13. PotenOal
saving
in
opOmal
case
is
7
mill
hrs
for
the
Stallo-­‐cluster.
13

14. 14