<s>
System	B-Device
X	I-Device
(	O
pronounced	O
"	O
System	O
Ten	O
"	O
)	O
was	O
a	O
supercomputer	B-Architecture
assembled	O
by	O
Virginia	O
Tech	O
's	O
Advanced	O
Research	O
Computing	O
facility	O
in	O
the	O
summer	O
of	O
2003	O
.	O
</s>
<s>
Costing	O
US	O
$5.2	O
million	O
,	O
it	O
was	O
originally	O
composed	O
of	O
1,100	O
Apple	O
Power	B-Device
Mac	I-Device
G5	I-Device
computers	O
with	O
dual	O
2.0GHz	O
processors	O
.	O
</s>
<s>
System	B-Device
X	I-Device
was	O
decommissioned	O
on	O
May	O
21	O
,	O
2012	O
.	O
</s>
<s>
System	B-Device
X	I-Device
ran	O
at	O
12.25	O
Teraflops	O
,	O
(	O
20.24	O
peak	O
)	O
,	O
and	O
was	O
ranked	O
#3	O
on	O
November	O
16	O
,	O
2003	O
and	O
#280	O
in	O
the	O
July	O
2008	O
edition	O
of	O
the	O
TOP500	B-Operating_System
list	O
of	O
the	O
world	O
's	O
most	O
powerful	O
supercomputers	B-Architecture
.	O
</s>
<s>
The	O
system	O
used	O
error-correcting	O
(	O
ECC	B-General_Concept
)	O
RAM	O
,	O
which	O
is	O
important	O
for	O
accuracy	O
due	O
to	O
the	O
rate	O
of	O
bits	O
flipped	O
by	O
cosmic	O
rays	O
or	O
other	O
interference	O
sources	O
in	O
its	O
vast	O
number	O
of	O
RAM	O
chips	O
.	O
</s>
<s>
The	O
supercomputer	B-Architecture
's	O
name	O
originates	O
from	O
the	O
use	O
of	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
for	O
each	O
node	O
,	O
and	O
because	O
it	O
was	O
the	O
first	O
university	O
computer	O
to	O
achieve	O
10	O
teraflops	O
on	O
the	O
high	O
performance	O
LINPACK	B-Application
benchmark	I-Application
.	O
</s>
<s>
The	O
supercomputer	B-Architecture
is	O
also	O
known	O
as	O
Big	B-Device
Mac	I-Device
or	O
Terascale	O
Cluster	O
.	O
</s>
<s>
In	O
2003	O
it	O
was	O
also	O
touted	O
as	O
"	O
the	O
world	O
's	O
most	O
powerful	O
and	O
cheapest	O
homebuilt	O
supercomputer.	O
"	O
</s>
<s>
System	B-Device
X	I-Device
was	O
constructed	O
with	O
a	O
relatively	O
low	O
budget	O
of	O
just	O
$5.2	O
million	O
,	O
in	O
the	O
span	O
of	O
only	O
three	O
months	O
,	O
thanks	O
in	O
large	O
part	O
to	O
using	O
off-the-shelf	O
Power	B-Device
Mac	I-Device
G5	I-Device
computers	O
.	O
</s>
<s>
By	O
comparison	O
,	O
the	O
Earth	B-Device
Simulator	I-Device
,	O
the	O
fastest	B-Operating_System
supercomputer	I-Operating_System
at	O
the	O
time	O
,	O
cost	O
approximately	O
$400	O
million	O
to	O
build	O
.	O
</s>
<s>
In	O
2004	O
,	O
Virginia	O
Tech	O
upgraded	O
its	O
computer	O
to	O
Apple	O
's	O
newly	O
released	O
,	O
Xserve	B-Device
G5	B-Device
servers	O
.	O
</s>
<s>
The	O
upgraded	O
version	O
ranked	O
#7	O
in	O
the	O
2004	O
TOP500	B-Operating_System
list	O
and	O
its	O
server-grade	O
error-correcting	O
memory	O
solved	O
the	O
problem	O
of	O
cosmic	O
ray	O
interference	O
.	O
</s>
<s>
In	O
October	O
2004	O
,	O
Virginia	O
Tech	O
partially	O
rebuilt	O
System	B-Device
X	I-Device
at	O
a	O
cost	O
of	O
about	O
$	O
600,000	O
.	O
</s>
<s>
These	O
improvements	O
brought	O
the	O
computer	O
's	O
speed	O
up	O
to	O
12.25	O
Teraflops	O
,	O
which	O
placed	O
System	B-Device
X	I-Device
#14	O
on	O
the	O
2005	O
TOP500	B-Operating_System
list	O
.	O
</s>
<s>
Virginia	O
Tech	O
's	O
system	O
was	O
the	O
model	O
for	O
Xseed	O
,	O
a	O
smaller	O
system	O
also	O
made	O
from	O
Xserve	B-Device
servers	O
and	O
built	O
by	O
Bowie	O
State	O
University	O
in	O
Maryland	O
.	O
</s>
<s>
Xseed	O
was	O
ranked	O
#166	O
in	O
the	O
2005	O
TOP500	B-Operating_System
.	O
</s>
<s>
System	B-Device
G	I-Device
has	O
324	O
Mac	O
Pros	O
(	O
2592	O
processor	O
cores	O
)	O
with	O
QDR	O
InfiniBand	B-Architecture
in	O
Virginia	O
Tech	O
's	O
Center	O
for	O
High-End	O
Computing	O
Systems	O
.	O
</s>
