<s>
The	O
Fastra	B-Device
II	I-Device
is	O
a	O
desktop	B-Device
supercomputer	B-Architecture
designed	O
for	O
tomography	B-Algorithm
.	O
</s>
<s>
It	O
was	O
built	O
in	O
late	O
2009	O
by	O
the	O
ASTRA	O
(	O
All	O
Scale	O
Tomographic	B-Algorithm
Reconstruction	I-Algorithm
Antwerp	O
)	O
group	O
of	O
researchers	O
of	O
the	O
IBBT	O
(	O
Interdisciplinary	O
institute	O
for	O
BroadBand	O
Technology	O
)	O
VisionLab	O
at	O
the	O
University	O
of	O
Antwerp	O
and	O
by	O
Belgian	O
computer	O
shop	O
Tones	O
,	O
in	O
collaboration	O
with	O
Asus	O
,	O
a	O
Taiwanese	O
multinational	O
computer	O
product	O
manufacturer	O
,	O
as	O
the	O
successor	O
to	O
the	O
Fastra	B-Device
I	I-Device
(	O
built	O
in	O
2008	O
)	O
.	O
</s>
<s>
The	O
Fastra	B-Device
II	I-Device
was	O
determined	O
to	O
be	O
over	O
three	O
times	O
faster	O
than	O
the	O
Fastra	B-Device
I	I-Device
,	O
which	O
in	O
turn	O
was	O
slightly	O
faster	O
than	O
a	O
512-core	O
cluster	O
.	O
</s>
<s>
However	O
,	O
because	O
of	O
the	O
number	O
of	O
GPUs	B-Architecture
in	O
the	O
computer	O
,	O
the	O
system	O
initially	O
suffered	O
from	O
several	O
issues	O
,	O
including	O
the	O
system	O
refusing	O
to	O
reboot	O
and	O
overheating	O
due	O
to	O
a	O
lack	O
of	O
space	O
between	O
the	O
video	O
cards	O
.	O
</s>
<s>
Unlike	O
other	O
modern	O
supercomputers	B-Architecture
such	O
as	O
the	O
Cray	B-Device
Jaguar	I-Device
and	O
the	O
IBM	B-General_Concept
Roadrunner	I-General_Concept
,	O
which	O
cost	O
millions	O
of	O
euros	O
,	O
the	O
Fastra	B-Device
II	I-Device
only	O
uses	O
consumer	O
hardware	O
,	O
costing	O
€	O
6,000	O
in	O
total	O
.	O
</s>
<s>
The	O
Fastra	B-Device
II	I-Device
's	O
predecessor	O
,	O
the	O
Fastra	B-Device
I	I-Device
,	O
has	O
4	O
dual-GPU	O
GeForce	O
9800	O
GX2	O
video	O
cards	O
,	O
for	O
a	O
total	O
of	O
8	O
GPUs	B-Architecture
.	O
</s>
<s>
At	O
that	O
time	O
,	O
the	O
ASTRA	O
group	O
needed	O
a	O
motherboard	B-Device
that	O
had	O
four	O
PCI	O
Express	O
x16	O
slots	O
with	O
double-spacing	O
between	O
each	O
of	O
them	O
.	O
</s>
<s>
The	O
only	O
such	O
motherboard	B-Device
the	O
ASTRA	O
group	O
could	O
find	O
at	O
that	O
time	O
was	O
the	O
MSI	O
K9A2	O
Platinum	O
,	O
which	O
has	O
four	O
such	O
slots	O
.	O
</s>
<s>
In	O
2009	O
,	O
the	O
Asus	O
P6T7	O
WS	O
Supercomputer	B-Architecture
motherboard	B-Device
,	O
which	O
the	O
Fastra	B-Device
II	I-Device
uses	O
,	O
was	O
released	O
,	O
which	O
has	O
seven	O
PCI	O
Express	O
x16	O
slots	O
.	O
</s>
<s>
The	O
Fastra	B-Device
II	I-Device
has	O
six	O
faster	O
dual-GPU	O
GeForce	O
GTX	O
295	O
video	O
cards	O
,	O
and	O
a	O
single-GPU	O
GeForce	O
GTX	O
275	O
,	O
for	O
a	O
total	O
of	O
13	O
GPUs	B-Architecture
.	O
</s>
<s>
In	O
the	O
Fastra	B-Device
II	I-Device
,	O
the	O
GPUs	B-Architecture
mainly	O
perform	O
tomographic	B-Algorithm
reconstruction	I-Algorithm
.	O
</s>
<s>
The	O
technique	O
which	O
allows	O
GPUs	B-Architecture
to	O
perform	O
general-purpose	O
tasks	O
like	O
this	O
outside	O
of	O
gaming	O
,	O
instead	O
of	O
CPUs	B-General_Concept
,	O
is	O
called	O
GPGPU	B-Architecture
,	O
general-purpose	B-Architecture
computing	I-Architecture
on	I-Architecture
graphics	I-Architecture
processing	I-Architecture
units	I-Architecture
.	O
</s>
<s>
Overheating	O
caused	O
by	O
the	O
lack	O
of	O
space	O
between	O
the	O
video	O
cards	O
forces	O
researchers	O
using	O
the	O
FASTRA	B-Device
II	I-Device
to	O
keep	O
the	O
side	O
panel	O
door	O
open	O
,	O
so	O
that	O
the	O
video	O
cards	O
can	O
get	O
regular	O
air	O
,	O
decreasing	O
the	O
overall	O
temperature	O
inside	O
the	O
case	O
.	O
</s>
<s>
Due	O
to	O
the	O
number	O
of	O
GPUs	B-Architecture
in	O
the	O
system	O
,	O
its	O
initial	O
boot	O
was	O
unsuccessful	O
.	O
</s>
<s>
This	O
was	O
because	O
its	O
motherboard	B-Device
normally	O
uses	O
a	O
32	O
bit	O
BIOS	B-Operating_System
,	O
which	O
only	O
had	O
approximately	O
3	O
GB	O
of	O
address	O
space	O
for	O
the	O
video	O
cards	O
.	O
</s>
<s>
However	O
,	O
Asus	O
managed	O
to	O
provide	O
them	O
a	O
specialized	O
BIOS	B-Operating_System
that	O
entirely	O
skipped	O
the	O
address	O
space	O
allocation	O
of	O
the	O
GTX	O
295	O
video	O
cards	O
.	O
</s>
<s>
The	O
BIOS-replacement	O
coreboot	B-Device
was	O
not	O
tested	O
.	O
</s>
<s>
All	O
seven	O
PCI	O
Express	O
x16	O
slots	O
in	O
the	O
Asus	O
P6T7	O
motherboard	B-Device
were	O
used	O
in	O
the	O
building	O
of	O
the	O
Fastra	B-Device
II	I-Device
computer	O
.	O
</s>
<s>
However	O
,	O
the	O
video	O
cards	O
in	O
the	O
Fastra	B-Device
II	I-Device
are	O
wide	O
enough	O
to	O
require	O
two	O
such	O
slots	O
each	O
.	O
</s>
<s>
To	O
solve	O
this	O
issue	O
,	O
the	O
researchers	O
came	O
up	O
with	O
flexible	O
PCI	O
Express	O
cables	O
,	O
and	O
Tones	O
developed	O
a	O
custom	O
cage	O
which	O
allowed	O
the	O
video	O
cards	O
to	O
suspend	O
over	O
the	O
motherboard	B-Device
.	O
</s>
<s>
Like	O
the	O
Fastra	B-Device
I	I-Device
,	O
the	O
Fastra	B-Device
II	I-Device
uses	O
a	O
Lian	O
Li	O
PC-P80	O
Armorsuit	O
case	O
,	O
which	O
has	O
10	O
expansion	O
slots	O
.	O
</s>
<s>
The	O
motherboard	B-Device
in	O
the	O
Fastra	B-Device
II	I-Device
was	O
at	O
that	O
time	O
the	O
only	O
workstation	B-Device
motherboard	B-Device
that	O
had	O
seven	O
full-sized	O
PCI	O
Express	O
x16	O
slots	O
.	O
</s>
<s>
Instead	O
of	O
an	O
eighth	O
dual-GPU	O
video	O
card	O
,	O
the	O
single-GPU	O
GTX	O
275	O
is	O
in	O
the	O
computer	O
because	O
,	O
out	O
of	O
all	O
the	O
video	O
cards	O
in	O
the	O
Fastra	B-Device
II	I-Device
,	O
the	O
GTX	O
275	O
is	O
the	O
only	O
one	O
the	O
Fastra	B-Device
II	I-Device
's	O
BIOS	B-Operating_System
can	O
fully	O
initialize	O
.	O
</s>
<s>
The	O
total	O
amount	O
of	O
GPUs	B-Architecture
is	O
13	O
.	O
</s>
<s>
According	O
to	O
the	O
benchmarks	O
on	O
its	O
official	O
website	O
,	O
the	O
Fastra	B-Device
II	I-Device
is	O
faster	O
and	O
more	O
power	O
efficient	O
than	O
its	O
competitors	O
,	O
including	O
the	O
Fastra	B-Device
I	I-Device
and	O
the	O
Tesla	B-Device
C1060	O
video	O
card	O
.	O
</s>
<s>
The	O
benchmarks	O
were	O
performed	O
on	O
the	O
Fastra	B-Device
II	I-Device
,	O
the	O
Fastra	B-Device
I	I-Device
,	O
a	O
512-core	O
cluster	O
(	O
consisting	O
of	O
Opteron	B-General_Concept
CPUs	B-General_Concept
)	O
,	O
an	O
Nvidia	B-Device
Tesla	I-Device
C1060	O
workstation	B-Device
card	O
on	O
an	O
Intel	B-Device
Core	I-Device
i7	I-Device
940	O
CPU	O
,	O
and	O
on	O
an	O
Intel	B-Device
Core	I-Device
i7	I-Device
940	O
CPU	O
itself	O
.	O
</s>
<s>
The	O
Fastra	B-Device
II	I-Device
is	O
over	O
three	O
times	O
faster	O
than	O
the	O
Fastra	B-Device
I	I-Device
in	O
CT	O
slice	O
reconstruction	O
speed	O
.	O
</s>
<s>
Although	O
the	O
Fastra	B-Device
II	I-Device
consumes	O
more	O
power	O
than	O
the	O
Fastra	B-Device
I	I-Device
,	O
it	O
's	O
nearly	O
3	O
times	O
as	O
energy	O
efficient	O
as	O
the	O
Fastra	B-Device
I	I-Device
,	O
and	O
over	O
300	O
times	O
as	O
energy	O
efficient	O
as	O
the	O
512-core	O
cluster	O
.	O
</s>
<s>
The	O
operating	O
system	O
is	O
CentOS	O
,	O
a	O
community	O
driven	O
Linux	B-Application
distribution	I-Application
and	O
Red	O
Hat	O
Enterprise	O
Linux	O
clone	O
.	O
</s>
<s>
The	O
Fastra	B-Device
II	I-Device
received	O
a	O
positive	O
public	O
impression	O
.	O
</s>
<s>
Techie.com	O
called	O
it	O
the	O
"	O
world	O
's	O
most	O
powerful	O
desktop-sized	O
supercomputer	B-Architecture
"	O
,	O
describing	O
it	O
as	O
a	O
computer	O
with	O
"	O
so	O
much	O
power	O
in	O
such	O
a	O
small	O
space.	O
"	O
</s>
<s>
iTech	O
News	O
Net	O
called	O
it	O
"	O
the	O
Most	O
Powerful	O
Desktop	B-Device
Supercomputer	B-Architecture
"	O
.	O
</s>
<s>
Fastra	B-Device
II	I-Device
relies	O
on	O
Nvidia	O
's	O
Scalable	B-Device
Link	I-Device
Interface	I-Device
(	O
SLI	O
)	O
and	O
is	O
therefore	O
limited	O
to	O
the	O
number	O
of	O
GPUs	B-Architecture
supported	O
by	O
it	O
,	O
the	O
vendor	O
,	O
and	O
the	O
free	B-Application
and	I-Application
open-source	I-Application
device	O
drivers	O
.	O
</s>
<s>
The	O
Fastra	B-Device
II	I-Device
's	O
motherboard	B-Device
is	O
designed	O
for	O
workstations	B-Device
,	O
and	O
the	O
computer	O
is	O
mainly	O
being	O
used	O
in	O
hospitals	O
for	O
medical	O
imaging	O
.	O
</s>
<s>
It	O
remains	O
to	O
be	O
seen	O
whether	O
another	O
Fastra	O
,	O
featuring	O
NVLink	O
,	O
first	O
available	O
with	O
Pascal-based	O
GPUs	B-Architecture
,	O
will	O
be	O
built	O
.	O
</s>
