
Available on Google Cloud: Intel Optane DC Persistent Memory - eicnix
https://cloud.google.com/blog/topics/partners/available-first-on-google-cloud-intel-optane-dc-persistent-memory
======
boulos
Disclosure: I work on Google Cloud.

As I replied in a sub-thread, I think Intel's marketing diagram [1] is
probably useful to help separate the Optane flavors. This is about the "near
DRAM" variant.

While the blog post highlights running SAP HANA (SAP's in-memory focused
database), you can use them for whatever you want. The persistent part is that
it's persistent across reboots. The _hope_ is that this might make it easier
to have tiered database/caching systems, since the gap between DRAM and this
new "memory" is much closer than say DRAM and SSD.

[1] [https://newsroom.intel.com/wp-
content/uploads/sites/11/2018/...](https://newsroom.intel.com/wp-
content/uploads/sites/11/2018/05/filling-the-gaps-between-memory-and-storage-
after.png)

~~~
xvf22
I'm curious how endurance is handled in this case. Is there a wear level
guarantee when provisioning it? I guess this is applicable to any consumable
though this seems to be a pretty expensive one.

~~~
boulos
That’s part of the design of Optane (née 3DXpoint): it’s supposed to be lower
latency than traditional SSD and higher durability. I don’t know enough about
the how nor the details to say more, sorry.

This article from Anandtech [1] covers the SSD variant though which states:

> The endurance rating for both capacities is 200 GB/day for the five-year
> warranty period. Given the small capacity of the drives, this works out to
> 1.7 or 3.4 drive writes per day, which is considerably higher than normal
> for consumer SSDs.

[1] [https://www.anandtech.com/show/12512/the-intel-optane-
ssd-80...](https://www.anandtech.com/show/12512/the-intel-optane-
ssd-800p-review)

~~~
wtallis
> Optane (née 3DXpoint)

Optane is the brand name for Intel products that use 3D XPoint memory. Micron
products that use 3D XPoint memory will be sold under Micron's QuantX
trademark, if they ever ship. There's also a possibility that Micron could
eventually start selling 3D XPoint memory to other SSD manufacturers, and the
resulting products wouldn't bear either Optane or QuantX branding.

The more relevant comparison for endurance may be the enterprise Optane SSD DC
P4800X, which was initially released with a 30 DWPD rating but has since been
increased to 60 DWPD. Intel hasn't described what kind of error correction
that drive is doing under the hood, but it's probably more robust than what
the entry-level consumer Optane drives do, and possibly more robust than what
the DIMMs can do within their latency budget.

------
thibautg
I still do not completely understand what SAP HANA really is:

\- an in-memory database technology?

\- the name for SAP’s cloud platform?

\- an on-premise DB to run SAP ERP (to replace Oracle)?

\- a full-stack proprietary web development platform?

\- a marketing term to solve all problems with SAP products?

Does anyone have an hands on experience with HANA, beyond the usual marketing
BS? Is is that revolutionary? If it runs on such specialized hardware, is the
speed increase that impressive?

~~~
dijit
I have no practical experience with SAP HANA. But I’m a sysadmin and I’ve been
to conferences where SAP has had stands and I have a tendency to ask too many
questions.

SAP HANA is an in memory database. That’s all it is. It’s similar to Qlikview
if you’ve used that. It’s licensed per socket, so scaling up is better than
scaling out.

SAP will also host HANA for you, for a fee.

See. The thing is: SAP is a company for HR departments. The kinds of
departments that aren’t technical, do not have technical staff to develop
thing for them. (It’s an example) but your HR department talks to SAP, they
deliver some service, sometimes something that the barely tech-literate
members of HR is able to build on and then suddenly your sysadmins have to
support those things in perpetuity.

Well. They market themselves as this anyway. And I have experience of our HR
department buying all kinds of stuff from SAP and their child companies.
(Concur, for example).

So I understand your incredulous-ness. This company is not made for us. And
most of their tech isn’t either.

~~~
toyg
_> SAP is a company for HR departments._

And finance. And operations. And compliance, and ...

 _> The kinds of departments that aren’t technical_

Which, in most businesses, are _almost all of them_. That's why they are so
entrenched and so profitable, despite selling an utterly unfashionable and
over-complicated stack.

~~~
tcbawo
Is SAP in the business of selling solutions or technical stack/platform? From
what I understand, there is a large ecosystem of private SAP consultants.

~~~
vbezhenar
AFAIK SAP will sell you a platform and you'll hire consultants who will build
solution for your company using that platform.

------
georgewfraser
One of the most interesting applications of NVM is databases. The design of
most existing databases is predicated on needing to always persist writes to
disk; the existence of non-volatile memory allows very different, potentially
much faster designs. There's a great explanation of this in
[https://db.cs.cmu.edu/papers/2017/p1753-arulraj.pdf](https://db.cs.cmu.edu/papers/2017/p1753-arulraj.pdf)

------
zilchers
Does anyone know much about the tech on this? I assume when they say
persistent they mean across VM restarts, but are they actually doing some sort
of disk persistence too?

~~~
locacorten
This is byte-addressable persistent memory. They look like DRAM DIMMs and they
plug into DIMM slots. You access them using your memory controller and not
your storage controller. People sometimes refer to them as non-volatile memory
(NVM). Intel used to call it Apache Pass.

They're a nightmare to program because OSes do not have a good abstraction for
them (at least not yet). Accessing them through the file-system seems sub-
optimal (this is byte-addressable memory and not a block device). Accessing
them through virtual memory is also pretty bad because they're much slower
than DRAM.

~~~
devit
Is there are a reason to not just use DRAM along with a battery to achieve the
same persistence but as fast as DRAM?

~~~
wtallis
There are NVDIMMs that have DRAM and a matching quantity of NAND flash memory
to save the contents to in the event of a power failure. They require an
external capacitor module and are limited in data capacity by how much DRAM
you can fit on the module. You can fit far more 3D XPoint memory on a module
than DRAM, and it doesn't require the external capacitors to achieve
persistence, and it should be significantly cheaper on a per-GB basis.

~~~
cdoxsey
Just to reiterate the point... this is an instance with terabytes of near-
memory-speed storage.

If persistent memory pans out as a technology it will completely upend the way
we think about building software and the cost tradeoffs of hardware. (as much
as or more so than the transition from spinning disks to ssds)

~~~
Dylan16807
How do you define "pans out"? What performance and price differences between
it, flash, and DRAM do you have in mind?

Because I'll keep reminding people that putting a DRAM cache in front of some
flash can _very closely approximate_ a large persistent memory. If people
_wanted_ to build software for that kind of system, they could do it today.
The hardware is not the blocker.

~~~
SergeAx
Cache will always stay just cache, unless it is the same size that an
underlying persistent storage. You cannot read or write larger-than-cache
chunks without performance degradation. Also you have a start-up cache-warming
problem.

~~~
Dylan16807
Most workloads don't need the entire storage to be at maximum speed all the
time. In other words, in most situations cache is plenty for speed purposes.
And the mapping layer can hide the chunk sizes. But we still don't see people
writing software based around persistence. Maybe a lot of people are simply
stuck in their ways, or maybe the benefits aren't actually that big.

As for cache-warming, that's also a configuration issue. When you reboot,
leave the 'cache' portion of DRAM alone. Then as soon as the service resumes,
the cache is already hot. When you shut down a node for an extended period,
consider spending five minutes writing the cache to disc. And the article is
about cloud servers anyway, where a shutdown typically implies losing all
local storage whether it's persistent or not.

------
nodesocket
How does this compare to NVMe based AWS EC2 instances like m5d, c5d, r5d?

~~~
boulos
Disclosure: I work on Google Cloud.

NVMe is (now) a more general purpose "speak to flash like things". This Optane
_memory_ stuff is made of "flash", but unlike our Local SSD offering (or AWS's
i3) it's at a latency and throughput _closer_ to DRAM.

Despite it being marketing material, I find the pyramid diagram [1] helpful.
This blog post is about "Optane Persistent Memory".

[1] [https://newsroom.intel.com/wp-
content/uploads/sites/11/2018/...](https://newsroom.intel.com/wp-
content/uploads/sites/11/2018/05/filling-the-gaps-between-memory-and-storage-
after.png)

~~~
ssvss
What is its latency compared to RAM, 10X ? Most latency comparisons mentioned
in other comments compare RAM to pcie based optane memory, not the DRAM optane
memory.

Edit: Article[1] here says the latency was 40µs with 13M IOPS, if you consider
RAM latency to be 100ns[2], then it looks like 40X

[1] -
[https://blogs.technet.microsoft.com/filecab/2018/10/30/windo...](https://blogs.technet.microsoft.com/filecab/2018/10/30/windows-
server-2019-and-intel-optane-dc-persistent-memory/) [2] -
[https://gist.github.com/jboner/2841832](https://gist.github.com/jboner/2841832)

------
espeed
Redis on Optane [1]. The GraphBLAS stars continue to align [2]. GPUs/TPUs
next. Distributed to come.

[1] Redis on Optane [https://redislabs.com/blog/redis-enterprise-flash-intel-
opta...](https://redislabs.com/blog/redis-enterprise-flash-intel-optane/)

[2] GraphBLAS & RedisGraph
[https://news.ycombinator.com/item?id=18099520](https://news.ycombinator.com/item?id=18099520)

------
musiciangames
Would this be a good fit for Smalltalk, as it is image based? It seems it can
remove a level of complexity, if you can treat your image, and so all your
objects, as constantly persisted?

~~~
scroot
Can't you already do this with an OODB? I'm asking sincerely, since I have
never quite understood why OODBs aren't used more often.

------
geggam
What is the benefit ?

Why are we constantly creating pets out of what should be cattle ?

~~~
segmondy
too bad you got downvoted, i would imagine in-memory DB and large cache.

~~~
Dylan16807
> too bad you got downvoted

It's pretty weird to call out people for making 'pet' servers because they're
daring to attach _storage_ to them.

~~~
rebelde
His native language isn't English, and people probably misunderstood his
literally-translated idiom. Pet servers?

~~~
sciurus
Pet's vs cattle is an analogy that originated with English-speakers.

[http://cloudscaling.com/blog/cloud-computing/the-history-
of-...](http://cloudscaling.com/blog/cloud-computing/the-history-of-pets-vs-
cattle/)

