Name: 什麼是持久性內存。持久性內存編程系列｜英特爾軟件 (What is Persistent Memory: Persistent Memory Programming Series | Intel Software)
Uploaded: 2021-01-14T07:13:42.000Z
Duration: 3 min
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In this video, I'll explain
what persistent memory is

and why there's so much
excitement around it.

Don't forget to watch
the rest of this playlist

Let's start by describing
what persistent memory is.

available on modern hardware
due to the emergence

of new memory technologies such
as Intel's 3D XPoint memory.

with the attributes of
both storage and memory.

These products are
persistent, like storage,

meaning they hold their contents
even across power cycles.

And they're byte
addressable, like memory,

meaning programs can access
data structures in place.

But what really makes
persistent memory stand out

is that it's fast enough
to access directly

to do the Block I/O required
for traditional storage.

If you compare a modern
NAND-based SSD which

plugs into the PCIe bus and
communicates using MDM Express

takes to read a block
is over 80 microseconds.

Notice how most of the time
is spent accessing the media

We could work on making
the device driver faster

and the difference would
be hardly noticeable.

The Intel Optane SSD also
plugs into the PCIe bus,

but uses 3D XPoint, so
the time spent accessing

Now notice that the overhead of
the software stack in the PCIe

protocol is a significant
portion of the overall latency.

To get the most out of
3D XPoint technology,

it now makes sense to tackle
the overhead of both software

By connecting the media
to the memory bus,

And since memory is accessed
in 64-byte cache lines,

You can see how low latency
a 64-byte read is here,

although I also show a 4K
read for an apples-to-apples

have a new tier available
for data placement.

In addition to the
memory and storage tiers,

capacities larger than DRAM
and performance significantly

Applications can access
persistent memory resident data

structures in place like they
do with traditional memory.

This eliminates the need
to page blocks of data

back and forth between
memory and storage.

allows applications to
connect up with ranges

That's the topic of the
rest of this video series.

Re-architecting your
software will take some time.

Get started right away by
watching this persistent memory

And don't forget to check out
the links in the description