<s>
The	O
HPCG	B-Operating_System
(	O
high	O
performance	O
conjugate	O
gradient	O
)	O
benchmark	O
is	O
a	O
supercomputing	B-Architecture
benchmark	O
test	O
proposed	O
by	O
Michael	O
Heroux	O
from	O
Sandia	O
National	O
Laboratories	O
,	O
and	O
Jack	O
Dongarra	O
and	O
Piotr	O
Luszczek	O
from	O
the	O
University	O
of	O
Tennessee	O
.	O
</s>
<s>
It	O
is	O
intended	O
to	O
model	O
the	O
data	B-General_Concept
access	I-General_Concept
patterns	O
of	O
real-world	O
applications	B-Application
such	O
as	O
sparse	B-Algorithm
matrix	I-Algorithm
calculations	O
,	O
thus	O
testing	O
the	O
effect	O
of	O
limitations	O
of	O
the	O
memory	O
subsystem	O
and	O
internal	O
interconnect	B-General_Concept
of	O
the	O
supercomputer	B-Architecture
on	O
its	O
computing	O
performance	O
.	O
</s>
<s>
Because	O
it	O
is	O
internally	O
I/O	B-General_Concept
bound	I-General_Concept
(	O
the	O
data	O
for	O
the	O
benchmark	O
resides	O
in	O
main	O
memory	O
as	O
it	O
is	O
too	O
large	O
for	O
processor	O
caches	O
)	O
,	O
HPCG	B-Operating_System
testing	O
generally	O
achieves	O
only	O
a	O
tiny	O
fraction	O
of	O
the	O
peak	O
FLOPS	O
the	O
computer	O
could	O
theoretically	O
deliver	O
.	O
</s>
<s>
HPCG	B-Operating_System
is	O
intended	O
to	O
complement	O
benchmarks	O
such	O
as	O
the	O
LINPACK	B-Device
benchmarks	I-Device
that	O
put	O
relatively	O
little	O
stress	O
on	O
the	O
internal	O
interconnect	B-General_Concept
.	O
</s>
<s>
The	O
source	O
of	O
the	O
HPCG	B-Operating_System
benchmark	I-Operating_System
is	O
available	O
on	O
GitHub	B-Application
.	O
</s>
<s>
As	O
of	O
June	O
2018	O
,	O
the	O
Summit	B-Device
supercomputer	I-Device
held	O
the	O
top	O
spot	O
in	O
the	O
HPCG	B-Operating_System
performance	O
rankings	O
,	O
followed	O
by	O
the	O
Sierra	B-Device
and	O
the	O
K	B-Device
computer	I-Device
.	O
</s>
<s>
In	O
June	O
of	O
2020	O
,	O
Summit	B-Device
was	O
superseded	O
by	O
Fugaku	B-Device
,	O
which	O
as	O
of	O
November	O
2022	O
,	O
with	O
a	O
speed	O
of	O
16.0	O
HPCG-petaflops	O
,	O
an	O
increase	O
of	O
540%	O
over	O
Summit	B-Device
,	O
now	O
4rd	O
and	O
Frontier	O
2nd	O
(	O
1st	O
on	O
Top500	B-Operating_System
)	O
closely	O
following	O
and	O
LUMI	O
3rd	O
.	O
</s>
