<s>
In	O
computing	O
,	O
Physical	B-General_Concept
Address	I-General_Concept
Extension	I-General_Concept
(	O
PAE	O
)	O
,	O
sometimes	O
referred	O
to	O
as	O
Page	B-General_Concept
Address	I-General_Concept
Extension	I-General_Concept
,	O
</s>
<s>
is	O
a	O
memory	O
management	O
feature	O
for	O
the	O
x86	B-Operating_System
architecture	I-Operating_System
.	O
</s>
<s>
PAE	O
was	O
first	O
introduced	O
by	O
Intel	O
in	O
the	O
Pentium	B-Device
Pro	I-Device
,	O
and	O
later	O
by	O
AMD	O
in	O
the	O
Athlon	B-Architecture
processor	O
.	O
</s>
<s>
It	O
defines	O
a	O
page	B-General_Concept
table	I-General_Concept
hierarchy	O
of	O
three	O
levels	O
(	O
instead	O
of	O
two	O
)	O
,	O
with	O
table	O
entries	O
of	O
64	O
bits	O
each	O
instead	O
of	O
32	O
,	O
allowing	O
these	O
CPUs	O
to	O
directly	O
access	O
a	O
physical	O
address	B-General_Concept
space	I-General_Concept
larger	O
than	O
4gigabytes	O
(	O
232	O
bytes	O
)	O
.	O
</s>
<s>
The	O
page	B-General_Concept
table	I-General_Concept
structure	O
used	O
by	O
x86-64	B-Device
CPUs	O
when	O
operating	O
in	O
long	B-Application
mode	I-Application
further	O
extends	O
the	O
page	B-General_Concept
table	I-General_Concept
hierarchy	O
to	O
four	O
levels	O
,	O
extending	O
the	O
virtual	O
address	B-General_Concept
space	I-General_Concept
,	O
and	O
uses	O
additional	O
physical	O
address	O
bits	O
at	O
all	O
levels	O
of	O
the	O
page	B-General_Concept
table	I-General_Concept
,	O
extending	O
the	O
physical	O
address	B-General_Concept
space	I-General_Concept
.	O
</s>
<s>
It	O
also	O
uses	O
the	O
topmost	O
bit	O
of	O
the	O
64-bit	O
page	B-General_Concept
table	I-General_Concept
entry	O
as	O
a	O
no-execute	O
or	O
"	B-General_Concept
NX	I-General_Concept
"	I-General_Concept
bit	I-General_Concept
,	O
indicating	O
that	O
code	O
cannot	O
be	O
executed	O
from	O
the	O
associated	O
page	O
.	O
</s>
<s>
The	O
NX	B-General_Concept
feature	O
is	O
also	O
available	O
in	O
protected	B-Application
mode	I-Application
when	O
these	O
CPUs	O
are	O
running	O
a	O
32-bit	O
operating	B-General_Concept
system	I-General_Concept
,	O
provided	O
that	O
the	O
operating	B-General_Concept
system	I-General_Concept
enables	O
PAE	O
.	O
</s>
<s>
PAE	O
was	O
first	O
implemented	O
in	O
the	O
Intel	B-Device
Pentium	I-Device
Pro	I-Device
in	O
1995	O
,	O
although	O
the	O
accompanying	O
chipsets	O
usually	O
lacked	O
support	O
for	O
the	O
required	O
extra	O
address	O
bits	O
.	O
</s>
<s>
PAE	O
is	O
supported	O
by	O
the	O
Pentium	B-Device
Pro	I-Device
,	O
Pentium	B-General_Concept
II	I-General_Concept
,	O
Pentium	B-General_Concept
III	I-General_Concept
,	O
and	O
Pentium	B-General_Concept
4	I-General_Concept
processors	O
.	O
</s>
<s>
The	O
first	O
Pentium	B-Architecture
M	I-Architecture
family	O
processors	O
(	O
"	O
Banias	O
"	O
)	O
introduced	O
in	O
2003	O
also	O
support	O
PAE	O
;	O
however	O
,	O
they	O
do	O
not	O
show	O
the	O
PAE	O
support	O
flag	O
in	O
their	O
CPUID	B-Architecture
information	O
.	O
</s>
<s>
It	O
was	O
also	O
available	O
on	O
AMD	O
processors	O
including	O
the	O
AMD	B-Architecture
Athlon	I-Architecture
(	O
although	O
the	O
chipsets	O
are	O
limited	O
to	O
32-bit	O
addressing	O
)	O
and	O
later	O
AMD	O
processor	O
models	O
.	O
</s>
<s>
When	O
AMD	O
defined	O
their	O
64-bit	O
extension	O
of	O
the	O
industry	O
standard	O
x86	B-Operating_System
architecture	I-Operating_System
,	O
AMD64	B-Device
or	O
x86-64	B-Device
,	O
they	O
also	O
enhanced	O
the	O
paging	O
system	O
in	O
"	O
long	B-Application
mode	I-Application
"	O
based	O
on	O
PAE	O
.	O
</s>
<s>
and	O
includes	O
NX	B-General_Concept
bit	I-General_Concept
functionality	O
.	O
</s>
<s>
When	O
the	O
x86-64	B-Device
processor	O
is	O
initialized	O
,	O
the	O
PAE	O
feature	O
is	O
required	O
to	O
be	O
enabled	O
before	O
the	O
processor	O
is	O
switched	O
from	O
Legacy	O
Mode	O
to	O
Long	B-Application
Mode	I-Application
.	O
</s>
<s>
With	O
PAE	O
,	O
the	O
page	B-General_Concept
table	I-General_Concept
entry	O
of	O
the	O
x86	B-Operating_System
architecture	I-Operating_System
is	O
enlarged	O
from	O
32	O
to	O
64	O
bits	O
.	O
</s>
<s>
This	O
allows	O
more	O
room	O
for	O
the	O
physical	O
page	O
address	O
,	O
or	O
"	O
page	B-General_Concept
frame	I-General_Concept
number	I-General_Concept
"	O
field	O
,	O
in	O
the	O
page	B-General_Concept
table	I-General_Concept
entry	O
.	O
</s>
<s>
In	O
the	O
initial	O
implementations	O
of	O
PAE	O
the	O
page	B-General_Concept
frame	I-General_Concept
number	I-General_Concept
field	O
was	O
expanded	O
from	O
20	O
to	O
24	O
bits	O
.	O
</s>
<s>
Later	O
processor	O
families	O
use	O
interconnects	O
such	O
as	O
Hypertransport	B-Device
or	O
QuickPath	B-Architecture
Interconnect	I-Architecture
,	O
which	O
lack	O
dedicated	O
memory	O
address	O
signals	O
,	O
so	O
this	O
relationship	O
is	O
less	O
apparent	O
.	O
</s>
<s>
The	O
32-bit	O
size	O
of	O
the	O
virtual	O
address	O
is	O
not	O
changed	O
,	O
so	O
regular	O
application	O
software	O
continues	O
to	O
use	O
instructions	O
with	O
32-bit	O
addresses	O
and	O
(	O
in	O
a	O
flat	B-General_Concept
memory	I-General_Concept
model	I-General_Concept
)	O
is	O
limited	O
to	O
4gigabytes	O
of	O
virtual	O
address	B-General_Concept
space	I-General_Concept
.	O
</s>
<s>
Operating	B-General_Concept
systems	I-General_Concept
supporting	O
this	O
mode	O
use	O
page	B-General_Concept
tables	I-General_Concept
to	O
map	O
the	O
regular	O
4GB	O
virtual	O
address	B-General_Concept
space	I-General_Concept
into	O
the	O
physical	O
memory	O
,	O
which	O
,	O
depending	O
on	O
the	O
operating	B-General_Concept
system	I-General_Concept
and	O
the	O
rest	O
of	O
the	O
hardware	O
platform	O
,	O
may	O
be	O
as	O
big	O
as	O
64GB	O
.	O
</s>
<s>
The	O
mapping	O
is	O
typically	O
applied	O
separately	O
for	O
each	O
process	B-Operating_System
,	O
so	O
that	O
the	O
additional	O
RAM	O
is	O
useful	O
even	O
though	O
no	O
single	O
process	B-Operating_System
can	O
access	O
it	O
all	O
simultaneously	O
.	O
</s>
<s>
Later	O
work	O
associated	O
with	O
AMD	O
's	O
development	O
of	O
x86-64	B-Device
architecture	O
expanded	O
the	O
theoretical	O
possible	O
size	O
of	O
physical	O
addresses	O
to	O
52	O
bits	O
.	O
</s>
<s>
In	O
protected	B-Application
mode	I-Application
with	O
paging	O
enabled	O
(	O
bit31	O
,	O
PG	O
,	O
of	O
control	B-Operating_System
register	I-Operating_System
CR0	B-Operating_System
is	O
set	O
)	O
,	O
but	O
without	O
PAE	O
,	O
x86	B-Operating_System
processors	O
use	O
a	O
two-level	O
page	O
translation	O
scheme	O
.	O
</s>
<s>
Control	B-Operating_System
register	I-Operating_System
CR3	O
holds	O
the	O
page-aligned	O
physical	O
address	O
of	O
a	O
single	O
4KB	O
long	O
page	O
directory	O
.	O
</s>
<s>
This	O
is	O
divided	O
into	O
1024	O
four-byte	O
page	O
directory	O
entries	O
that	O
in	O
turn	O
,	O
if	O
valid	O
,	O
hold	O
the	O
page-aligned	O
physical	O
addresses	O
of	O
page	B-General_Concept
tables	I-General_Concept
,	O
each	O
4KB	O
in	O
size	O
.	O
</s>
<s>
These	O
similarly	O
consist	O
of	O
1024	O
four-byte	O
page	B-General_Concept
table	I-General_Concept
entries	O
which	O
,	O
if	O
valid	O
,	O
hold	O
the	O
page-aligned	O
physical	O
addresses	O
of	O
4KB	O
long	O
pages	B-General_Concept
of	O
physical	O
memory	O
(	O
RAM	O
)	O
.	O
</s>
<s>
Each	O
entry	O
in	O
the	O
page	B-General_Concept
table	I-General_Concept
and	O
page	O
directory	O
becomes	O
64bits	O
long	O
(	O
8bytes	O
)	O
,	O
instead	O
of	O
32bits	O
,	O
to	O
allow	O
for	O
additional	O
address	O
bits	O
.	O
</s>
<s>
The	O
entries	O
in	O
the	O
page	O
directory	O
have	O
an	O
additional	O
flag	O
in	O
bit7	O
,	O
named	O
PS	O
(	O
for	O
page	B-General_Concept
size	I-General_Concept
)	O
.	O
</s>
<s>
If	O
the	O
system	O
has	O
set	O
this	O
bit	O
to	O
1	O
,	O
the	O
page	O
directory	O
entry	O
does	O
not	O
point	O
to	O
a	O
page	B-General_Concept
table	I-General_Concept
but	O
to	O
a	O
single	O
,	O
large	O
2MB	O
page	O
(	O
Page	B-General_Concept
Size	I-General_Concept
Extension	I-General_Concept
)	O
.	O
</s>
<s>
In	O
all	O
page	B-General_Concept
table	I-General_Concept
formats	O
supported	O
by	O
x86	B-Operating_System
and	O
x86-64	B-Device
,	O
the	O
12	O
least	O
significant	O
bits	O
of	O
the	O
page	B-General_Concept
table	I-General_Concept
entry	O
are	O
either	O
interpreted	O
by	O
the	O
memory	O
management	O
unit	O
or	O
are	O
reserved	O
for	O
operating	B-General_Concept
system	I-General_Concept
use	O
.	O
</s>
<s>
In	O
processors	O
that	O
implement	O
the	O
"	O
no-execute	O
"	O
or	O
"	O
execution	O
disable	O
"	O
feature	O
,	O
the	O
most	O
significant	O
bit	O
(	O
bit63	O
)	O
is	O
the	O
NX	B-General_Concept
bit	I-General_Concept
.	O
</s>
<s>
The	O
next	O
eleven	O
most	O
significant	O
bits	O
(	O
bits	O
52	O
through	O
62	O
)	O
are	O
reserved	O
for	O
operating	B-General_Concept
system	I-General_Concept
use	O
by	O
both	O
Intel	O
and	O
AMD	O
's	O
architecture	O
specifications	O
.	O
</s>
<s>
Thus	O
,	O
from	O
64	O
bits	O
in	O
the	O
page	B-General_Concept
table	I-General_Concept
entry	O
,	O
12	O
low-order	O
and	O
12	O
high-order	O
bits	O
have	O
other	O
uses	O
,	O
leaving	O
40	O
bits	O
(	O
bits	O
12	O
though	O
51	O
)	O
for	O
the	O
physical	O
page	O
number	O
.	O
</s>
<s>
Combined	O
with	O
12	O
bits	O
of	O
"	O
offset	O
within	O
page	O
"	O
from	O
the	O
linear	B-General_Concept
address	I-General_Concept
,	O
a	O
maximum	O
of	O
52bits	O
are	O
available	O
to	O
address	O
physical	O
memory	O
.	O
</s>
<s>
On	O
x86-64	B-Device
processors	O
in	O
native	O
long	B-Application
mode	I-Application
,	O
the	O
address	O
translation	O
scheme	O
uses	O
PAE	O
but	O
adds	O
a	O
fourth	O
table	O
,	O
the	O
512-entry	O
page-map	O
level	O
4	O
table	O
,	O
and	O
extends	O
the	O
page	O
directory	O
pointer	O
table	O
to	O
512entries	O
instead	O
of	O
the	O
original	O
4entries	O
it	O
has	O
in	O
protected	B-Application
mode	I-Application
.	O
</s>
<s>
Currently	O
48bits	O
of	O
virtual	B-General_Concept
page	I-General_Concept
number	O
are	O
translated	O
,	O
giving	O
a	O
virtual	O
address	B-General_Concept
space	I-General_Concept
of	O
up	O
to	O
256TB	O
.	O
</s>
<s>
In	O
the	O
page	B-General_Concept
table	I-General_Concept
entries	O
,	O
in	O
the	O
original	O
specification	O
,	O
40bits	O
of	O
physical	O
page	O
number	O
are	O
implemented	O
.	O
</s>
<s>
Software	O
can	O
identify	O
via	O
the	O
CPUID	B-Architecture
flag	O
PAE	O
whether	O
a	O
CPU	O
supports	O
PAE	O
mode	O
or	O
not	O
.	O
</s>
<s>
A	O
free-of-charge	O
program	O
for	O
Microsoft	B-Application
Windows	I-Application
is	O
available	O
which	O
will	O
list	O
many	O
processor	O
capabilities	O
,	O
including	O
PAE	O
support	O
.	O
</s>
<s>
In	O
Linux	B-Operating_System
,	O
commands	O
such	O
as	O
cat	O
/proc/cpuinfo	O
can	O
list	O
the	O
pae	O
flag	O
when	O
present	O
,	O
as	O
well	O
as	O
other	O
tools	O
such	O
as	O
the	O
SYSLINUX	B-Application
Hardware	O
Detection	O
Tool	O
.	O
</s>
<s>
To	O
run	O
the	O
processor	O
in	O
PAE	O
mode	O
,	O
operating	B-General_Concept
system	I-General_Concept
support	O
is	O
required	O
.	O
</s>
<s>
To	O
use	O
PAE	O
to	O
access	O
more	O
than	O
4	O
GB	O
of	O
RAM	O
,	O
further	O
support	O
is	O
required	O
in	O
the	O
operating	B-General_Concept
system	I-General_Concept
,	O
in	O
the	O
chipset	O
,	O
and	O
on	O
the	O
motherboard	O
.	O
</s>
<s>
Nevertheless	O
,	O
even	O
if	O
no	O
more	O
than	O
4	O
GB	O
of	O
RAM	O
is	O
available	O
and	O
accessible	O
,	O
a	O
PAE-capable	O
CPU	O
may	O
be	O
run	O
in	O
PAE	O
mode	O
,	O
for	O
example	O
to	O
allow	O
use	O
of	O
the	O
No	B-General_Concept
execute	I-General_Concept
feature	O
.	O
</s>
<s>
32-bit	O
versions	O
of	O
Microsoft	B-Application
Windows	I-Application
support	O
PAE	O
if	O
booted	O
with	O
the	O
appropriate	O
option	O
.	O
</s>
<s>
The	O
following	O
table	O
shows	O
the	O
memory	O
limits	O
for	O
32-bit	O
versions	O
of	O
Microsoft	B-Application
Windows	I-Application
:	O
</s>
<s>
The	O
original	O
releases	O
of	O
Windows	B-Application
XP	I-Application
and	O
Windows	B-Application
XP	I-Application
SP1	O
used	O
PAE	O
mode	O
to	O
allow	O
RAM	O
to	O
extend	O
beyond	O
the	O
4GB	O
address	O
limit	O
.	O
</s>
<s>
However	O
,	O
it	O
led	O
to	O
compatibility	O
problems	O
with	O
3rd	O
party	O
drivers	O
which	O
led	O
Microsoft	O
to	O
remove	O
this	O
capability	O
in	O
Windows	B-Application
XP	I-Application
Service	O
Pack	O
2	O
.	O
</s>
<s>
Windows	B-Application
XP	I-Application
SP2	O
and	O
later	O
,	O
by	O
default	O
,	O
on	O
processors	O
with	O
the	O
no-execute	O
(	O
NX	B-General_Concept
)	O
or	O
execute-disable	O
(	O
XD	O
)	O
feature	O
,	O
runs	O
in	O
PAE	O
mode	O
in	O
order	O
to	O
allow	O
NX	B-General_Concept
.	O
</s>
<s>
The	O
NX	B-General_Concept
bit	I-General_Concept
resides	O
in	O
bit63	O
of	O
the	O
page	B-General_Concept
table	I-General_Concept
entry	O
and	O
,	O
without	O
PAE	O
,	O
page	B-General_Concept
table	I-General_Concept
entries	O
on	O
32-bit	O
systems	O
have	O
only	O
32bits	O
;	O
therefore	O
PAE	O
mode	O
is	O
required	O
in	O
order	O
to	O
exploit	O
the	O
NX	B-General_Concept
feature	O
.	O
</s>
<s>
However	O
,	O
"	O
client	O
"	O
versions	O
of	O
32-bit	B-Application
Windows	I-Application
(	O
Windows	B-Application
XP	I-Application
SP2	O
and	O
later	O
,	O
Windows	B-Application
Vista	I-Application
,	O
Windows	B-Device
7	I-Device
)	O
limit	O
physical	O
address	B-General_Concept
space	I-General_Concept
to	O
the	O
first	O
4GB	O
for	O
driver	O
compatibility	O
even	O
though	O
these	O
versions	O
do	O
run	O
in	O
PAE	O
mode	O
if	O
NX	B-General_Concept
support	O
is	O
enabled	O
.	O
</s>
<s>
Windows	B-Application
8	I-Application
and	O
later	O
releases	O
will	O
only	O
run	O
on	O
processors	O
which	O
support	O
PAE	O
,	O
in	O
addition	O
to	O
NX	B-General_Concept
and	O
SSE2	B-General_Concept
.	O
</s>
<s>
Mac	B-Application
OS	I-Application
X	I-Application
Tiger	I-Application
through	O
Mac	B-Device
OS	I-Device
X	I-Device
Snow	I-Device
Leopard	I-Device
support	O
PAE	O
and	O
the	O
NX	B-General_Concept
bit	I-General_Concept
on	O
IA-32	O
processors	O
;	O
Snow	B-Device
Leopard	I-Device
was	O
the	O
last	O
version	O
to	O
support	O
IA-32	O
processors	O
.	O
</s>
<s>
On	O
x86-64	B-Device
processors	O
,	O
all	O
versions	O
of	O
macOS	B-Application
use	O
4-level	O
paging	O
(	O
IA-32e	B-Device
paging	O
rather	O
than	O
PAE	O
)	O
to	O
address	O
memory	O
above	O
4GB	O
.	O
</s>
<s>
Mac	B-Device
Pro	I-Device
and	O
Xserve	B-Device
systems	O
can	O
use	O
up	O
to	O
64GB	O
of	O
RAM	O
.	O
</s>
<s>
The	O
Linux	B-Operating_System
kernel	I-Operating_System
includes	O
full	O
PAE-mode	O
support	O
starting	O
with	O
version	O
2.3.23	O
,	O
in	O
1999	O
enabling	O
access	O
of	O
up	O
to	O
64GB	O
of	O
memory	O
on	O
32-bit	O
machines	O
.	O
</s>
<s>
A	O
PAE-enabled	O
Linux	B-Operating_System
kernel	I-Operating_System
requires	O
that	O
the	O
CPU	O
also	O
support	O
PAE	O
.	O
</s>
<s>
The	O
Linux	B-Operating_System
kernel	I-Operating_System
supports	O
PAE	O
as	O
a	O
build	O
option	O
and	O
major	O
distributions	O
provide	O
a	O
PAE	O
kernel	B-Operating_System
either	O
as	O
the	O
default	O
or	O
as	O
an	O
option	O
.	O
</s>
<s>
The	O
NX	B-General_Concept
bit	I-General_Concept
feature	O
requires	O
a	O
kernel	B-Operating_System
built	O
with	O
PAE	O
support	O
.	O
</s>
<s>
Linux	B-Application
distributions	I-Application
now	O
commonly	O
use	O
a	O
PAE-enabled	O
kernel	B-Operating_System
as	O
the	O
default	O
,	O
a	O
trend	O
that	O
began	O
in	O
2009	O
.	O
many	O
,	O
including	O
Ubuntu	B-Operating_System
(	O
and	O
derivatives	O
like	O
Xubuntu	B-Application
and	O
Linux	B-Application
Mint	I-Application
)	O
,	O
Red	O
Hat	O
Enterprise	O
Linux	B-Operating_System
6.0	O
,	O
and	O
CentOS	O
,	O
have	O
stopped	O
distributing	O
non-PAE	O
kernels	B-Operating_System
,	O
thus	O
making	O
PAE-supporting	O
hardware	O
mandatory	O
.	O
</s>
<s>
Linux	B-Application
distributions	I-Application
that	O
require	O
PAE	O
may	O
refuse	O
to	O
boot	O
on	O
Pentium	B-Architecture
M	I-Architecture
family	O
processors	O
because	O
they	O
do	O
not	O
show	O
the	O
PAE	O
support	O
flag	O
in	O
their	O
CPUID	B-Architecture
information	O
(	O
even	O
though	O
it	O
is	O
supported	O
internally	O
)	O
.	O
</s>
<s>
However	O
,	O
this	O
can	O
be	O
easily	O
bypassed	O
,	O
at	O
least	O
in	O
Ubuntu	B-Operating_System
,	O
with	O
the	O
forcepae	O
option	O
.	O
</s>
<s>
Distributions	O
that	O
still	O
provide	O
a	O
non-PAE	O
option	O
,	O
including	O
Debian	O
(	O
and	O
derivatives	O
like	O
LMDE	O
2	O
(	O
Linux	B-Application
Mint	I-Application
Debian	O
Edition	O
)	O
)	O
,	O
Slackware	B-Application
,	O
and	O
LXLE	O
,	O
typically	O
do	O
so	O
with	O
"	O
i386	O
"	O
,	O
"	O
i486	O
"	O
,	O
or	O
"	O
retro	O
"	O
labels	O
.	O
</s>
<s>
The	O
article	O
Lightweight	B-Operating_System
Linux	I-Operating_System
distribution	I-Operating_System
does	O
list	O
some	O
others	O
,	O
allowing	O
to	O
install	O
Linux	B-Operating_System
onto	O
old	O
computers	O
.	O
</s>
<s>
FreeBSD	B-Operating_System
and	O
NetBSD	B-Device
also	O
support	O
PAE	O
as	O
a	O
kernel	B-Operating_System
build	O
option	O
.	O
</s>
<s>
FreeBSD	B-Operating_System
supports	O
PAE	O
in	O
the	O
4.x	O
series	O
starting	O
with	O
4.9	O
,	O
in	O
the	O
5.x	O
series	O
starting	O
with	O
5.1	O
,	O
and	O
in	O
all	O
6.x	O
and	O
later	O
releases	O
.	O
</s>
<s>
Support	O
requires	O
the	O
kernel	B-Operating_System
PAE	O
configuration-option	O
.	O
</s>
<s>
Loadable	B-Application
kernel	I-Application
modules	I-Application
can	O
only	O
be	O
loaded	O
into	O
a	O
kernel	B-Operating_System
with	O
PAE	O
enabled	O
if	O
the	O
modules	B-Application
were	O
built	O
with	O
PAE	O
enabled	O
;	O
the	O
binary	O
modules	B-Application
in	O
FreeBSD	B-Operating_System
distributions	O
are	O
not	O
built	O
with	O
PAE	O
enabled	O
,	O
and	O
thus	O
cannot	O
be	O
loaded	O
into	O
PAE	O
kernels	B-Operating_System
.	O
</s>
<s>
OpenBSD	B-Operating_System
has	O
had	O
support	O
for	O
PAE	O
since	O
2006	O
with	O
the	O
standard	O
GENERIC	O
i386	O
kernel	B-Operating_System
.	O
</s>
<s>
Solaris	B-Application
supports	O
PAE	O
beginning	O
with	O
Solaris	B-Application
version	O
7	O
.	O
</s>
<s>
Haiku	B-Language
added	O
initial	O
support	O
for	O
PAE	O
sometime	O
after	O
the	O
R1	O
Alpha	O
2	O
release	O
.	O
</s>
<s>
ArcaOS	B-Device
has	O
limited	O
support	O
for	O
PAE	O
for	O
the	O
purpose	O
of	O
creating	O
RAM	O
disks	O
above	O
the	O
4GB	O
boundary	O
.	O
</s>
