<s>
A	O
RAM	B-Application
drive	I-Application
(	O
also	O
called	O
a	O
RAM	B-Application
disk	I-Application
)	O
is	O
a	O
block	O
of	O
random-access	B-Architecture
memory	I-Architecture
(	O
primary	O
storage	O
or	O
volatile	B-General_Concept
memory	I-General_Concept
)	O
that	O
a	O
computer	O
's	O
software	O
is	O
treating	O
as	O
if	O
the	O
memory	O
were	O
a	O
disk	B-Device
drive	I-Device
(	O
secondary	O
storage	O
)	O
.	O
</s>
<s>
RAM	B-Application
drives	I-Application
provide	O
high-performance	O
temporary	O
storage	O
for	O
demanding	O
tasks	O
and	O
protect	O
non-volatile	O
storage	O
devices	O
from	O
wearing	O
down	O
,	O
since	O
RAM	B-Architecture
is	O
not	O
prone	O
to	O
wear	O
from	O
writing	O
,	O
unlike	O
non-volatile	O
flash	B-Device
memory	I-Device
.	O
</s>
<s>
It	O
is	O
sometimes	O
referred	O
to	O
as	O
a	O
virtual	B-Application
RAM	I-Application
drive	I-Application
or	O
software	B-Application
RAM	I-Application
drive	I-Application
to	O
distinguish	O
it	O
from	O
a	O
hardware	O
RAM	B-Application
drive	I-Application
that	O
uses	O
separate	O
hardware	O
containing	O
RAM	B-Architecture
,	O
which	O
is	O
a	O
type	O
of	O
battery-backed	O
solid-state	B-Device
drive	I-Device
.	O
</s>
<s>
Historically	O
primary	O
storage	O
based	O
mass	B-Device
storage	I-Device
devices	I-Device
were	O
conceived	O
to	O
bridge	O
the	O
performance	O
gap	O
between	O
internal	O
memory	O
and	O
secondary	O
storage	O
devices	O
.	O
</s>
<s>
So	O
RAM	B-Architecture
devices	O
do	O
offer	O
an	O
advantage	O
to	O
store	O
frequently	O
changing	O
data	O
,	O
like	O
temporary	O
or	O
cached	O
information	O
.	O
</s>
<s>
The	O
performance	O
of	O
a	O
RAM	B-Application
drive	I-Application
is	O
generally	O
orders	O
of	O
magnitude	O
faster	O
than	O
other	O
forms	O
of	O
digital	O
storage	O
,	O
such	O
as	O
SSD	B-Device
,	O
tape	O
,	O
optical	B-Device
,	O
hard	B-Device
disk	I-Device
,	O
and	O
floppy	B-Device
drives	I-Device
.	O
</s>
<s>
This	O
performance	O
gain	O
is	O
due	O
to	O
multiple	O
factors	O
,	O
including	O
access	O
time	O
,	O
maximum	O
throughput	O
,	O
and	O
file	B-Application
system	I-Application
characteristics	O
.	O
</s>
<s>
File	B-Application
access	I-Application
time	O
is	O
greatly	O
reduced	O
since	O
a	O
RAM	B-Application
drive	I-Application
is	O
solid	O
state	O
(	O
no	O
moving	O
parts	O
)	O
.	O
</s>
<s>
A	O
physical	O
hard	B-Device
drive	I-Device
,	O
optical	B-Device
(	O
e.g	O
,	O
CD-ROM	B-Device
,	O
DVD	O
,	O
and	O
Blu-ray	O
)	O
or	O
other	O
media	O
(	O
e.g.	O
</s>
<s>
magnetic	B-General_Concept
bubble	I-General_Concept
,	O
acoustic	O
storage	O
,	O
magnetic	B-Architecture
tape	I-Architecture
)	O
must	O
move	O
the	O
information	O
to	O
a	O
particular	O
position	O
before	O
reading	O
or	O
writing	O
can	O
occur	O
.	O
</s>
<s>
RAM	B-Application
drives	I-Application
can	O
access	O
data	O
with	O
only	O
the	O
address	O
,	O
eliminating	O
this	O
latency	O
.	O
</s>
<s>
Second	O
,	O
the	O
maximum	O
throughput	O
of	O
a	O
RAM	B-Application
drive	I-Application
is	O
limited	O
by	O
the	O
speed	O
of	O
the	O
RAM	B-Architecture
,	O
the	O
data	B-General_Concept
bus	I-General_Concept
,	O
and	O
the	O
CPU	B-General_Concept
of	O
the	O
computer	O
.	O
</s>
<s>
Other	O
forms	O
of	O
storage	O
media	O
are	O
further	O
limited	O
by	O
the	O
speed	O
of	O
the	O
storage	O
bus	O
,	O
such	O
as	O
IDE	B-Protocol
(	O
PATA	B-Protocol
)	O
,	O
SATA	O
,	O
USB	B-Protocol
or	O
FireWire	B-Protocol
.	O
</s>
<s>
Third	O
,	O
the	O
file	B-Application
system	I-Application
in	O
use	O
,	O
such	O
as	O
NTFS	B-Application
,	O
HFS	B-Application
,	O
UFS	B-Operating_System
,	O
ext2	O
,	O
etc.	O
,	O
uses	O
extra	O
accesses	O
,	O
reads	O
and	O
writes	O
to	O
the	O
drive	O
,	O
which	O
although	O
small	O
,	O
can	O
add	O
up	O
quickly	O
,	O
especially	O
in	O
the	O
event	O
of	O
many	O
small	O
files	O
vs.	O
few	O
larger	O
files	O
(	O
temporary	O
internet	O
folders	O
,	O
web	O
caches	B-General_Concept
,	O
etc	O
.	O
</s>
<s>
Because	O
the	O
storage	O
is	O
in	O
RAM	B-Architecture
,	O
it	O
is	O
volatile	B-General_Concept
memory	I-General_Concept
,	O
which	O
means	O
it	O
will	O
be	O
lost	O
in	O
the	O
event	O
of	O
power	O
loss	O
,	O
whether	O
intentional	O
(	O
computer	O
reboot	O
or	O
shutdown	O
)	O
or	O
accidental	O
(	O
power	O
failure	O
or	O
system	O
crash	O
)	O
.	O
</s>
<s>
This	O
is	O
,	O
in	O
general	O
,	O
a	O
weakness	O
(	O
the	O
data	O
must	O
periodically	O
be	O
backed	O
up	O
to	O
a	O
persistent-storage	O
medium	O
to	O
avoid	O
loss	O
)	O
,	O
but	O
is	O
sometimes	O
desirable	O
:	O
for	O
example	O
,	O
when	O
working	O
with	O
a	O
decrypted	O
copy	O
of	O
an	O
encrypted	O
file	O
,	O
or	O
using	O
the	O
RAM	B-Application
drive	I-Application
to	O
store	O
the	O
system	O
's	O
temporary	B-Application
files	I-Application
.	O
</s>
<s>
In	O
many	O
cases	O
,	O
the	O
data	O
stored	O
on	O
the	O
RAM	B-Application
drive	I-Application
is	O
created	O
from	O
data	O
permanently	O
stored	O
elsewhere	O
,	O
for	O
faster	B-General_Concept
access	I-General_Concept
,	O
and	O
is	O
re-created	O
on	O
the	O
RAM	B-Application
drive	I-Application
when	O
the	O
system	O
reboots	O
.	O
</s>
<s>
Apart	O
from	O
the	O
risk	O
of	O
data	O
loss	O
,	O
the	O
major	O
limitation	O
of	O
RAM	B-Application
drives	I-Application
is	O
capacity	O
,	O
which	O
is	O
constrained	O
by	O
the	O
amount	O
of	O
installed	O
RAM	B-Architecture
.	O
</s>
<s>
Multi-terabyte	O
SSD	B-Device
storage	O
has	O
become	O
common	O
,	O
but	O
RAM	B-Architecture
is	O
still	O
measured	O
in	O
gigabytes	O
.	O
</s>
<s>
RAM	B-Application
drives	I-Application
use	O
normal	O
system	O
memory	O
as	O
if	O
it	O
were	O
a	O
partition	O
on	O
a	O
physical	O
hard	B-Device
drive	I-Device
rather	O
than	O
accessing	O
the	O
data	B-General_Concept
bus	I-General_Concept
normally	O
used	O
for	O
secondary	O
storage	O
.	O
</s>
<s>
Though	O
RAM	B-Application
drives	I-Application
can	O
often	O
be	O
supported	O
directly	O
in	O
the	O
operating	O
system	O
via	O
special	O
mechanisms	O
in	O
the	O
OS	B-Operating_System
kernel	I-Operating_System
,	O
it	O
is	O
generally	O
simpler	O
to	O
access	O
a	O
RAM	B-Application
drive	I-Application
through	O
a	O
virtual	B-Application
device	I-Application
driver	O
.	O
</s>
<s>
This	O
makes	O
the	O
non-disk	O
nature	O
of	O
RAM	B-Application
drives	I-Application
invisible	O
to	O
both	O
the	O
OS	O
and	O
applications	O
.	O
</s>
<s>
Usually	O
no	O
battery	O
backup	O
is	O
needed	O
due	O
to	O
the	O
temporary	O
nature	O
of	O
the	O
information	O
stored	O
in	O
the	O
RAM	B-Application
drive	I-Application
,	O
but	O
an	O
uninterruptible	O
power	O
supply	O
can	O
keep	O
the	O
system	O
running	O
during	O
a	O
short	O
power	O
outage	O
.	O
</s>
<s>
Some	O
RAM	B-Application
drives	I-Application
use	O
a	O
compressed	O
file	B-Application
system	I-Application
such	O
as	O
cramfs	B-Application
to	O
allow	O
compressed	O
data	O
to	O
be	O
accessed	O
on	O
the	O
fly	O
,	O
without	O
decompressing	O
it	O
first	O
.	O
</s>
<s>
This	O
is	O
convenient	O
because	O
RAM	B-Application
drives	I-Application
are	O
often	O
small	O
due	O
to	O
the	O
higher	O
price	O
per	O
byte	O
than	O
conventional	O
hard	B-Device
drive	I-Device
storage	O
.	O
</s>
<s>
The	O
first	O
software	B-Application
RAM	I-Application
drive	I-Application
for	O
microcomputers	O
was	O
invented	O
and	O
written	O
by	O
Jerry	O
Karlin	O
in	O
the	O
UK	O
in	O
1979/80	O
.	O
</s>
<s>
The	O
software	O
,	O
known	O
as	O
the	O
Silicon	B-Device
Disk	I-Device
System	I-Device
was	O
further	O
developed	O
into	O
a	O
commercial	O
product	O
and	O
marketed	O
by	O
JK	O
Systems	O
Research	O
which	O
became	O
Microcosm	O
Research	O
Ltd	O
when	O
the	O
company	O
was	O
joined	O
by	O
Peter	O
Cheesewright	O
of	O
Microcosm	O
Ltd	O
.	O
</s>
<s>
The	O
idea	O
was	O
to	O
enable	O
the	O
early	O
microcomputers	O
to	O
use	O
more	O
RAM	B-Architecture
than	O
the	O
CPU	B-General_Concept
could	O
directly	O
address	O
.	O
</s>
<s>
Making	O
bank-switched	O
RAM	B-Architecture
behave	O
like	O
a	O
disk	B-Device
drive	I-Device
was	O
much	O
faster	O
than	O
the	O
disk	B-Device
drives	I-Device
-	O
especially	O
in	O
those	O
days	O
before	O
hard	B-Device
drives	I-Device
were	O
readily	O
available	O
on	O
such	O
machines	O
.	O
</s>
<s>
The	O
Silicon	O
Disk	B-Device
was	O
launched	O
in	O
1980	O
,	O
initially	O
for	O
the	O
CP/M	B-Application
operating	I-Application
system	I-Application
and	O
later	O
for	O
MS-DOS	B-Application
.	O
</s>
<s>
Due	O
to	O
the	O
limitations	O
in	O
memory	O
addressing	O
on	O
Atari	B-Device
8-bit	I-Device
,	O
Apple	B-Device
II	I-Device
series	I-Device
and	O
Commodore	O
computers	O
,	O
a	O
RAM	B-Application
drive	I-Application
was	O
also	O
a	O
popular	O
application	O
on	O
the	O
Atari	B-Device
130XE	I-Device
,	O
Commodore	O
64	O
and	O
Commodore	B-Device
128	I-Device
systems	O
with	O
RAM	B-General_Concept
Expansion	I-General_Concept
Units	I-General_Concept
and	O
on	O
Apple	B-Device
II	I-Device
series	I-Device
computers	O
with	O
more	O
than	O
64kB	O
of	O
RAM	B-Architecture
.	O
</s>
<s>
Apple	O
Computer	O
supported	O
a	O
software	B-Application
RAM	I-Application
drive	I-Application
natively	O
in	O
ProDOS	B-Operating_System
:	O
on	O
systems	O
with	O
128kB	O
or	O
more	O
of	O
RAM	B-Architecture
,	O
ProDOS	B-Operating_System
would	O
automatically	O
allocate	O
a	O
RAM	B-Application
drive	I-Application
named	O
.	O
</s>
<s>
IBM	O
added	O
a	O
RAM	B-Application
drive	I-Application
named	O
VDISK.SYS	B-Application
to	O
PC	B-Operating_System
DOS	I-Operating_System
(	O
version	O
3.0	O
)	O
in	O
August	O
1984	O
,	O
which	O
was	O
the	O
first	O
DOS	O
component	O
to	O
use	O
extended	B-Device
memory	I-Device
.	O
</s>
<s>
VDISK.SYS	B-Application
was	O
not	O
available	O
in	O
Microsoft	O
's	O
MS-DOS	B-Application
as	O
it	O
,	O
unlike	O
most	O
components	O
of	O
early	O
versions	O
of	O
PC	B-Operating_System
DOS	I-Operating_System
,	O
was	O
written	O
by	O
IBM	O
.	O
</s>
<s>
Microsoft	O
included	O
the	O
similar	O
program	O
RAMDRIVE.SYS	B-Application
in	O
MS-DOS	B-Application
3.2	O
(	O
released	O
in	O
1986	O
)	O
,	O
which	O
could	O
also	O
use	O
expanded	B-Device
memory	I-Device
.	O
</s>
<s>
DR-DOS	B-Application
and	O
the	O
DR	O
family	O
of	O
multi-user	O
operating	O
systems	O
also	O
came	O
with	O
a	O
RAM	B-Application
disk	I-Application
named	O
VDISK.SYS	B-Application
.	O
</s>
<s>
In	O
Multiuser	B-Operating_System
DOS	I-Operating_System
,	O
the	O
RAM	B-Application
disk	I-Application
defaults	O
to	O
the	O
drive	O
letter	O
M	O
:	O
(	O
for	O
memory	O
drive	O
)	O
.	O
</s>
<s>
AmigaOS	B-Application
has	O
had	O
a	O
built	O
in	O
RAM	B-Application
drive	I-Application
since	O
the	O
release	O
of	O
version	O
1.1	O
in	O
1985	O
and	O
still	O
has	O
it	O
in	O
AmigaOS	B-Application
4.1	I-Application
(	O
2010	O
)	O
.	O
</s>
<s>
Apple	O
Computer	O
added	O
the	O
functionality	O
to	O
the	O
Apple	B-Device
Macintosh	I-Device
with	O
System	B-Operating_System
7	I-Operating_System
's	O
Memory	O
control	B-Operating_System
panel	I-Operating_System
in	O
1991	O
,	O
and	O
kept	O
the	O
feature	O
through	O
the	O
life	O
of	O
Mac	B-Operating_System
OS	I-Operating_System
9	I-Operating_System
.	O
</s>
<s>
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
users	O
can	O
use	O
the	O
hdid	O
,	O
newfs	O
(	O
or	O
newfs	O
hfs	B-Application
)	O
and	O
mount	B-Device
utilities	O
to	O
create	O
,	O
format	O
and	O
mount	B-Device
a	O
RAM	B-Application
drive	I-Application
.	O
</s>
<s>
A	O
RAM	B-Application
drive	I-Application
innovation	O
introduced	O
in	O
1986	O
but	O
made	O
generally	O
available	O
in	O
1987	O
by	O
Perry	O
Kivolowitz	O
for	O
AmigaOS	B-Application
was	O
the	O
ability	O
of	O
the	O
RAM	B-Application
drive	I-Application
to	O
survive	O
most	O
crashes	O
and	O
reboots	O
.	O
</s>
<s>
Called	O
the	O
ASDG	O
Recoverable	O
Ram	B-Application
Disk	I-Application
,	O
the	O
device	O
survived	O
reboots	O
by	O
allocating	O
memory	O
dynamically	O
in	O
the	O
reverse	O
order	O
of	O
default	O
memory	O
allocation	O
(	O
a	O
feature	O
supported	O
by	O
the	O
underlying	O
OS	O
)	O
so	O
as	O
to	O
reduce	O
memory	O
fragmentation	O
.	O
</s>
<s>
The	O
super-block	O
,	O
and	O
all	O
other	O
RRD	O
disk	B-Device
"	O
blocks	O
"	O
maintained	O
check	O
sums	O
to	O
enable	O
the	O
invalidation	O
of	O
the	O
disk	B-Device
if	O
corruption	O
was	O
detected	O
.	O
</s>
<s>
The	O
shareware	O
version	O
appeared	O
on	O
Fred	O
Fish	O
Disks	B-Device
58	O
and	O
241	O
.	O
</s>
<s>
AmigaOS	B-Application
itself	O
would	O
gain	O
a	O
Recoverable	O
Ram	B-Application
Disk	I-Application
(	O
called	O
"	O
RAD	O
"	O
)	O
in	O
version	O
1.3	O
.	O
</s>
<s>
Many	O
Unix	B-Application
and	O
Unix-like	B-Operating_System
systems	I-Operating_System
provide	O
some	O
form	O
of	O
RAM	B-Application
drive	I-Application
functionality	O
,	O
such	O
as	O
on	O
Linux	B-Application
,	O
or	O
md(4 )	O
on	O
FreeBSD	B-Operating_System
.	O
</s>
<s>
RAM	B-Application
drives	I-Application
are	O
particularly	O
useful	O
in	O
high-performance	O
,	O
low-resource	O
applications	O
for	O
which	O
Unix-like	B-Operating_System
operating	I-Operating_System
systems	I-Operating_System
are	O
sometimes	O
configured	O
.	O
</s>
<s>
There	O
are	O
also	O
a	O
few	O
specialized	O
"	O
ultra-lightweight	O
"	O
Linux	B-Application
distributions	O
which	O
are	O
designed	O
to	O
boot	O
from	O
removable	O
media	O
and	O
stored	O
in	O
a	O
ramdisk	B-Application
for	O
the	O
entire	O
session	O
.	O
</s>
<s>
There	O
have	O
been	O
RAM	B-Application
drives	I-Application
which	O
use	O
DRAM	O
memory	O
that	O
is	O
exclusively	O
dedicated	O
to	O
function	O
as	O
an	O
extremely	O
low	O
latency	O
storage	O
device	O
.	O
</s>
<s>
An	O
early	O
example	O
of	O
a	O
hardware	O
RAM	B-Application
drive	I-Application
was	O
introduced	O
by	O
Assimilation	O
Process	O
,	O
Inc	O
.	O
in	O
1986	O
for	O
the	O
Macintosh	B-Device
.	O
</s>
<s>
Called	O
the	O
"	O
Excalibur	O
"	O
,	O
it	O
was	O
an	O
external	O
2MB	O
RAM	B-Application
drive	I-Application
,	O
and	O
retailed	O
for	O
between	O
$599	O
and	O
$699	O
US	O
.	O
</s>
<s>
With	O
the	O
RAM	B-Architecture
capacity	O
expandable	O
in	O
1MB	O
increments	O
,	O
its	O
internal	O
battery	O
was	O
said	O
to	O
be	O
effective	O
for	O
between	O
6	O
and	O
8	O
hours	O
,	O
and	O
,	O
unusual	O
for	O
the	O
time	O
,	O
it	O
was	O
connected	O
via	O
the	O
Macintosh	B-Device
floppy	B-Device
disk	I-Device
port	O
.	O
</s>
<s>
At	O
the	O
time	O
,	O
common	O
desktop	B-Device
computers	I-Device
used	O
64	O
to	O
128	O
megabytes	O
of	O
PC100	O
or	O
PC133	O
memory	O
.	O
</s>
<s>
In	O
2005	O
,	O
Gigabyte	O
Technology	O
produced	O
the	O
i-RAM	B-Device
,	O
max	O
4	O
GB	O
,	O
which	O
functioned	O
essentially	O
identically	O
to	O
the	O
Rocket	O
Drive	O
,	O
except	O
upgraded	O
to	O
use	O
the	O
newer	O
DDR	O
memory	O
technology	O
,	O
though	O
also	O
limited	O
to	O
a	O
maximum	O
of	O
4	O
GB	O
capacity	O
.	O
</s>
<s>
For	O
both	O
of	O
these	O
devices	O
,	O
the	O
dynamic	O
RAM	B-Architecture
requires	O
continuous	O
power	O
to	O
retain	O
data	O
;	O
when	O
power	O
is	O
lost	O
,	O
the	O
data	O
fades	O
away	O
.	O
</s>
<s>
The	O
i-RAM	B-Device
included	O
a	O
small	O
battery	O
directly	O
on	O
the	O
expansion	O
board	O
,	O
for	O
10-16	O
hours	O
of	O
protection	O
.	O
</s>
<s>
Both	O
devices	O
used	O
the	O
SATA	O
1.0	O
interface	O
to	O
transfer	O
data	O
from	O
the	O
dedicated	O
RAM	B-Application
drive	I-Application
to	O
the	O
system	O
.	O
</s>
<s>
The	O
SATA	O
interface	O
was	O
a	O
slow	O
bottleneck	O
that	O
limited	O
the	O
maximum	O
performance	O
of	O
both	O
RAM	B-Application
drives	I-Application
,	O
but	O
these	O
drives	O
still	O
provided	O
exceptionally	O
low	O
data	O
access	O
latency	O
and	O
high	O
sustained	O
transfer	O
speeds	O
,	O
compared	O
to	O
mechanical	O
hard	B-Device
drives	I-Device
.	O
</s>
<s>
In	O
2006	O
,	O
Gigabyte	O
Technology	O
produced	O
the	O
GC-RAMDISK	O
,	O
max	O
8GB	O
,	O
which	O
was	O
the	O
second	O
generation	O
creation	O
for	O
the	O
i-RAM	B-Device
.	O
</s>
<s>
It	O
has	O
a	O
maximum	O
of	O
8	O
GB	O
capacity	O
,	O
twice	O
that	O
of	O
the	O
i-RAM	B-Device
.	O
</s>
<s>
It	O
used	O
the	O
SATA-II	O
port	O
,	O
again	O
twice	O
that	O
of	O
the	O
i-RAM	B-Device
.	O
</s>
<s>
In	O
2007	O
,	O
ACard	O
Technology	O
produced	O
the	O
ANS-9010	O
Serial	O
ATA	O
RAM	B-Application
disk	I-Application
,	O
max	O
64	O
GB	O
.	O
</s>
<s>
In	O
2009	O
,	O
Acard	O
Technology	O
produced	O
the	O
ACARD	O
ANS-9010BA	O
5.25	O
''	O
Dynamic	O
SSD	B-Device
SATA-II	O
RAM	B-Application
Disk	I-Application
,	O
max	O
64GB	O
.	O
</s>
<s>
Both	O
variants	O
are	O
equipped	O
with	O
one	O
or	O
more	O
CompactFlash	B-Device
card	I-Device
interface	O
located	O
in	O
the	O
front	O
panel	O
,	O
allowing	O
non-volatile	O
data	O
being	O
stored	O
on	O
the	O
RAM	B-Application
drive	I-Application
to	O
be	O
copied	O
on	O
the	O
CompactFlash	B-Device
card	I-Device
in	O
case	O
of	O
power	O
failure	O
and	O
low	O
backup	O
battery	O
.	O
</s>
<s>
Two	O
pushbuttons	O
located	O
on	O
the	O
front	O
panel	O
allows	O
the	O
user	O
to	O
manually	O
backup	O
/	O
restore	O
data	O
on	O
the	O
RAM	B-Application
drive	I-Application
.	O
</s>
<s>
The	O
CompactFlash	B-Device
card	I-Device
itself	O
is	O
not	O
accessible	O
to	O
the	O
user	O
by	O
normal	O
means	O
as	O
the	O
CF	B-Device
card	I-Device
is	O
solely	O
intended	O
for	O
RAM	B-Architecture
backup	O
and	O
restoration	O
.	O
</s>
<s>
Note	O
that	O
the	O
CF	B-Device
card	I-Device
's	O
capacity	O
has	O
to	O
meet	O
/	O
exceed	O
the	O
RAM	B-Architecture
module	O
's	O
total	O
capacity	O
in	O
order	O
to	O
effectively	O
work	O
as	O
a	O
reliable	O
backup	O
.	O
</s>
<s>
In	O
2009	O
,	O
DDRdrive	O
,	O
LLC	O
produced	O
the	O
DDRDrive	O
X1	O
,	O
which	O
claims	O
to	O
be	O
the	O
fastest	O
solid	B-Device
state	I-Device
drive	I-Device
in	O
the	O
world	O
.	O
</s>
<s>
The	O
drive	O
is	O
a	O
primary	O
4GB	O
DDR	O
dedicated	O
RAM	B-Application
drive	I-Application
for	O
regular	O
use	O
,	O
which	O
can	O
back	O
up	O
to	O
and	O
recall	O
from	O
a	O
4GB	O
SLC	O
NAND	O
drive	O
.	O
</s>
<s>
The	O
intended	O
market	O
is	O
for	O
keeping	O
and	O
recording	O
log	B-Application
files	I-Application
.	O
</s>
<s>
If	O
there	O
is	O
a	O
power	O
loss	O
the	O
data	O
can	O
be	O
saved	O
to	O
an	O
internal	O
4GB	O
ssd	B-Device
in	O
60	O
seconds	O
,	O
via	O
the	O
use	O
of	O
a	O
battery	O
backup	O
.	O
</s>
<s>
Thereafter	O
the	O
data	O
can	O
be	O
recovered	O
back	O
in	O
to	O
RAM	B-Architecture
once	O
power	O
is	O
restored	O
.	O
</s>
