<s>
VPX	B-Architecture
(	O
Virtual	O
Path	O
Cross-Connect	O
)	O
,	O
also	O
known	O
as	O
VITA	B-Architecture
46	I-Architecture
,	O
refers	O
to	O
a	O
set	O
of	O
standards	O
for	O
connecting	O
components	O
of	O
a	O
computer	O
(	O
known	O
as	O
a	O
computer	B-General_Concept
bus	I-General_Concept
)	O
,	O
commonly	O
used	O
by	O
defense	O
contractors	O
.	O
</s>
<s>
VPX	B-Architecture
provides	O
VMEbus-based	O
systems	O
with	O
support	O
for	O
switched	B-Architecture
fabrics	I-Architecture
over	O
a	O
new	O
high	O
speed	O
connector	O
.	O
</s>
<s>
Defined	O
by	O
the	O
VMEbus	B-Architecture
International	O
Trade	O
Association	O
(	O
VITA	O
)	O
working	O
group	O
starting	O
in	O
2003	O
,	O
it	O
was	O
first	O
demonstrated	O
in	O
2004	O
,	O
and	O
became	O
an	O
ANSI	O
standard	O
in	O
2007	O
.	O
</s>
<s>
VPX	B-Architecture
was	O
intended	O
to	O
address	O
shortcomings	O
in	O
scalability	O
and	O
performance	O
of	O
on	O
both	O
side	O
of	O
the	O
bus	O
to	O
bus	O
bridging	O
technology	O
.	O
</s>
<s>
The	O
goal	O
was	O
to	O
include	O
newer	O
faster	O
VMEbus	B-Architecture
standards	O
and	O
new	O
generations	O
of	O
PCI	O
bus	O
standards	O
.	O
</s>
<s>
The	O
VMEbus	B-Architecture
International	O
Trade	O
Association	O
(	O
VITA	O
)	O
working	O
group	O
,	O
formed	O
in	O
March	O
2003	O
,	O
was	O
composed	O
of	O
companies	O
such	O
as	O
ADLINK	O
,	O
Boeing	O
,	O
Curtiss-Wright	O
,	O
Elma	O
Electronic	O
,	O
GE	O
Intelligent	O
Platforms	O
,	O
Kontron	O
,	O
Mercury	B-Application
Computer	I-Application
Systems	I-Application
,	O
and	O
Northrop	O
Grumman	O
,	O
it	O
was	O
designed	O
with	O
defense	O
applications	O
in	O
mind	O
,	O
with	O
an	O
enhanced	O
module	O
standard	O
that	O
enables	O
applications	O
and	O
platforms	O
with	O
superior	O
performance	O
.	O
</s>
<s>
VPX	B-Architecture
retained	O
VME	O
's	O
Eurocard	O
form	O
factors	O
,	O
which	O
are	O
based	O
on	O
multiples	O
of	O
three	O
rack	O
units	O
:	O
3U	O
means	O
three	O
rack	O
units	O
,	O
and	O
6U	O
six	O
rack	O
units	O
.	O
</s>
<s>
It	O
supported	O
PCI	O
Mezzanine	O
Card	O
(	O
PMC	O
)	O
and	O
XMC	O
mezzanines	O
(	O
PMC	O
with	O
high-speed	O
serial	O
fabric	O
interconnect	B-General_Concept
)	O
,	O
and	O
maintaining	O
the	O
maximum	O
possible	O
compatibility	O
with	O
VMEbus	B-Architecture
.	O
</s>
<s>
New	O
generations	O
of	O
embedded	B-Architecture
systems	I-Architecture
reflected	O
the	O
growing	O
significance	O
of	O
high	O
speed	O
serial	O
switched	B-Architecture
fabric	I-Architecture
interconnects	B-General_Concept
such	O
as	O
PCI	O
Express	O
,	O
RapidIO	B-General_Concept
,	O
Infiniband	B-Architecture
and	O
10	O
Gigabit	O
Ethernet	O
.	O
</s>
<s>
Switched	B-Architecture
fabrics	I-Architecture
technology	O
supports	O
the	O
implementation	O
of	O
multiprocessing	B-Operating_System
systems	O
that	O
require	O
the	O
fastest	O
possible	O
communications	O
between	O
multiple	O
processors	O
,	O
such	O
as	O
digital	B-General_Concept
signal	I-General_Concept
processing	I-General_Concept
applications	O
.	O
</s>
<s>
VPX	B-Architecture
gives	O
the	O
existing	O
base	O
of	O
VMEbus	B-Architecture
users	O
access	O
to	O
these	O
switched	B-Architecture
fabrics	I-Architecture
.	O
</s>
<s>
VPX	B-Architecture
technology	O
was	O
presented	O
at	O
a	O
VMEbus	B-Architecture
International	O
Trade	O
Association	O
(	O
VITA	O
)	O
trade	O
show	O
in	O
2004	O
,	O
by	O
a	O
company	O
called	O
American	O
Logic	O
Machines	O
USA	O
.	O
</s>
<s>
Technologies	O
in	O
VPX	B-Architecture
include	O
:	O
</s>
<s>
The	O
VPX	B-Architecture
standard	O
was	O
updated	O
in	O
2013	O
and	O
2019	O
.	O
</s>
<s>
In	O
common	O
with	O
other	O
similar	O
standards	O
,	O
VPX	B-Architecture
comprises	O
a	O
"	O
base	O
line	O
"	O
specification	O
,	O
which	O
defines	O
the	O
basic	O
mechanical	O
and	O
electrical	O
elements	O
of	O
VPX	B-Architecture
,	O
together	O
with	O
a	O
series	O
of	O
"	O
dot	O
level	O
"	O
specifications	O
,	O
one	O
or	O
more	O
of	O
which	O
must	O
be	O
implemented	O
to	O
create	O
a	O
functional	O
module	O
.	O
</s>
<s>
The	O
single	O
biggest	O
difference	O
between	O
original	O
VMEbus	B-Architecture
boards	O
and	O
VPX	B-Architecture
boards	O
is	O
a	O
new	O
connector	O
,	O
developed	O
by	O
Tyco	O
Electronics	O
and	O
known	O
as	O
the	O
MultiGig	O
RT2	O
which	O
was	O
used	O
in	O
VXS	B-Architecture
.	O
</s>
<s>
VPX	B-Architecture
boards	O
cannot	O
be	O
used	O
in	O
a	O
standard	O
VMEbus	B-Architecture
chassis	O
,	O
although	O
the	O
use	O
of	O
hybrid	O
chassis	O
is	O
foreseen	O
by	O
the	O
VPX	B-Architecture
standard	O
.	O
</s>
<s>
A	O
6U	O
VPX	B-Architecture
board	O
features	O
six	O
16-column	O
7-row	O
RT2/RVPX	O
connectors	O
and	O
one	O
8-column	O
7-row	O
RT2/RVPX	O
connector	O
,	O
while	O
a	O
3U	O
board	O
features	O
two	O
16-column	O
7-row	O
RT2/RVPX	O
connectors	O
and	O
one	O
8-column	O
7-row	O
RT2/RVPX	O
connector	O
.	O
</s>
<s>
Also	O
new	O
for	O
VPX	B-Architecture
boards	O
are	O
alignment/keying	O
blocks	O
which	O
are	O
designed	O
to	O
be	O
sufficiently	O
robust	O
to	O
prevent	O
pin	O
stubbing	O
.	O
</s>
<s>
The	O
new	O
connector	O
enables	O
a	O
6U	O
VPX	B-Architecture
board	O
to	O
feature	O
a	O
total	O
of	O
707	O
non-power	O
electrical	O
contacts	O
and	O
a	O
total	O
of	O
464	O
signal	O
contacts	O
.	O
</s>
<s>
The	O
VITA	O
62	O
section	O
of	O
the	O
VPX	B-Architecture
standard	O
allows	O
for	O
more	O
flexibility	O
in	O
maximizing	O
power	O
capability	O
of	O
the	O
system	O
,	O
as	O
compared	O
to	O
the	O
old	O
VMEbus	B-Architecture
standards	O
.	O
</s>
<s>
The	O
specification	O
of	O
6U	O
VPX	B-Architecture
calls	O
for	O
computer	B-General_Concept
cooling	I-General_Concept
via	O
a	O
conduction-cooled	O
envelope	O
compliant	O
with	O
the	O
IEEE	O
standard	O
IEEE-1101.2	O
,	O
which	O
is	O
compatible	O
with	O
existing	O
enclosures	O
.	O
</s>
<s>
This	O
provides	O
a	O
specification	O
not	O
only	O
for	O
ESD	O
metal	O
covers	O
on	O
two	O
sides	O
of	O
VPX	B-Architecture
boards	O
,	O
but	O
also	O
for	O
forced	O
air	O
,	O
conduction	O
-	O
and	O
liquid-cooling	O
implementations	O
.	O
</s>
<s>
Manufacturers	O
announced	O
products	O
based	O
on	O
the	O
VPX	B-Architecture
standard	O
,	O
in	O
both	O
3U	O
and	O
6U	O
form	O
factors	O
.	O
</s>
<s>
These	O
include	O
single-board	O
computers	O
(	O
based	O
on	O
both	O
Intel	O
and	O
PowerPC	B-Architecture
architectures	O
)	O
,	O
multiprocessors	B-Operating_System
,	O
graphics	O
processors	O
,	O
FPGA-based	O
processing	O
modules	O
,	O
mass	O
storage	O
,	O
switches	O
,	O
and	O
complete	O
integrated	O
subsystems	O
,	O
which	O
started	O
appearing	O
around	O
2007	O
.	O
</s>
<s>
The	O
OpenVPX	B-Architecture
working	O
group	O
was	O
formed	O
in	O
January	O
2009	O
to	O
develop	O
a	O
system-level	O
specification	O
that	O
addressed	O
interoperability	O
improvements	O
for	O
VPX	B-Architecture
.	O
</s>
<s>
Three	O
years	O
after	O
being	O
called	O
a	O
"	O
standard	O
"	O
,	O
most	O
VPX	B-Architecture
products	O
still	O
had	O
to	O
have	O
all	O
components	O
supplied	O
by	O
a	O
single	O
source	O
.	O
</s>
<s>
The	O
OpenVPX	B-Architecture
System	O
Specification	O
describes	O
technical	O
implementation	O
details	O
for	O
3U	O
and	O
6U	O
VPX	B-Architecture
payload	O
and	O
switch	O
modules	O
,	O
backplane	O
topologies	O
,	O
and	O
chassis	O
products	O
,	O
which	O
provides	O
guidance	O
on	O
how	O
to	O
build	O
interoperable	O
computing	O
and	O
communication	O
systems	O
.	O
</s>
<s>
OpenVPX	B-Architecture
was	O
a	O
development	O
of	O
,	O
and	O
complementary	O
to	O
,	O
VPX	B-Architecture
.	O
</s>
<s>
The	O
OpenVPX	B-Architecture
System	O
Specification	O
was	O
ratified	O
by	O
ANSI	O
in	O
June	O
2010	O
.	O
</s>
<s>
By	O
2011	O
,	O
it	O
was	O
seen	O
as	O
replacing	O
older	O
forms	O
of	O
VMEbus	B-Architecture
.	O
</s>
