<s>
The	O
DEGIMA	B-Device
(	O
DEstination	O
for	O
Gpu	B-Architecture
Intensive	O
MAchine	O
)	O
is	O
a	O
high	O
performance	O
computer	B-Architecture
cluster	I-Architecture
used	O
for	O
hierarchical	O
N-body	B-Algorithm
simulations	I-Algorithm
at	O
the	O
Nagasaki	O
Advanced	O
Computing	O
Center	O
,	O
Nagasaki	O
University	O
.	O
</s>
<s>
The	O
system	O
consists	O
of	O
a	O
144-node	O
cluster	O
of	O
PCs	O
connected	O
via	O
an	O
InfiniBand	B-Architecture
interconnect	O
.	O
</s>
<s>
Each	O
node	O
is	O
composed	O
of	O
2.66GHz	O
Intel	O
Core	O
i7	O
920	O
processor	O
,	O
two	O
GeForce	O
GTX295	O
graphics	O
cards	O
,	O
12	O
GB	O
DDR3-1333	O
memory	O
and	O
Mellanox	O
MHES14-XTC	O
SDR	O
InfiniBand	B-Architecture
host	O
adapter	O
on	O
MSI	O
X58	O
pro-E	O
motherboard	O
.	O
</s>
<s>
Each	O
graphics	O
card	O
has	O
two	O
GT200	O
GPU	B-Architecture
chips	O
.	O
</s>
<s>
As	O
a	O
whole	O
,	O
the	O
system	O
has	O
144	O
CPUs	B-Device
and	O
576	O
GPUs	B-Architecture
.	O
</s>
<s>
It	O
runs	O
astrophysical	O
N-body	B-Algorithm
simulations	I-Algorithm
with	O
over	O
3,000,000,000	O
particles	O
using	O
the	O
Multiple-Walk	O
parallel	O
treecode	O
.	O
</s>
