Intel Optane DC Persistent Memory - Configuration and Setup White Paper

3TECHNICAL WHITE PAPER
A volume created in Storage Mode can be set up with a feature known as Direct Access (DAX). When a volume
is DAX-enabled, the storage can be modied by direct access to the persistent memory, bypassing the traditional
form of block access. (Only some le systems in Windows and Linux support DAX).
An additional benet of a DCPMM Storage solution is it allows the user to save their limited PCIe slots for other
components like graphics cards. If your workows involve models with very large data sets or require frequent data
swaps between memory and storage, DCPMM is a technology you should investigate further.
App Direct Mode
The real revolution for DCPMM will occur with the utilization, in applications, of App Direct Mode. In this mode the
DCPMM technology oers the performance of memory with the persistence of storage. This provides Zero-copy
where applications and user data do not have to be moved from storage devices to memory before execution.
Applications that implement support for App Direct can deliver a near “Instant on” experience when launching the
application, loading very large datasets, switching between many applications, or even resuming an application
in the exact same state as it was in prior to shutting down the system.
New user experiences will also be possible. For instance, no more need for manual or automatic saves of your
work, except for exporting les when needed. Undo / Redo functions that remember changes even between
reboots. Virtually instant switching between data sets within an application. Transparently saving incremental (model
versioning) or dierent versions of a user’s work and models based only on the data actually modied,
thus drastically limiting computing or space used, with virtually no responsiveness impact when switching between
versions. Eventually, App Direct Mode will lead to a at memory model where there will be no dierentiation between
storage and memory. The new and disruptive user experiences that will emerge can hardly be imagined today
and will be a fascinating space to watch.
App Direct Mode is only compatible with new Persistent Memory (PMEM) aware le systems and applications.
Most software applications are not written to take advantage of an App Direct Mode. If your business is
development and sales of high-performance software applications, you will need to understand DCPMM and the
promise of App Direct Mode early so your software can be modied to take advantage of this innovative technology.
This document does not thoroughly cover the procedures for setting up App Direct mode or modifying applications
to use it. Some resources are named in Appendix H.
HP Factory Congured Solutions
HP will initially oer several factory congurations of DCPMM for Memory and Storage Modes. See HP Z6 G4
and HP Z8 G4 QuickSpecs for list of supported congurations.
Unique Attributes of Intel
®
Optane™ DCPMM
Intel
®
Optane™ DCPMM solutions are new and exciting. They are dierent than anything previously supported
in Workstations. Because they are new and dierent, users and system administrators need a broader
understanding on how to use DCPMM solutions:
• DRAM must be present in any conguration
°
Memory mode uses DRAM as cache for the DCPMM. The recommended ratio (DRAM:DCPMM) is 1:8.
°
Persistent Memory mode does not use DRAM as cache. DRAM serves as system memory as usual, so should
be congured to meet system and application needs.
°
In both usages, there are some loading rules that must be followed, detailed later.
• Physical placement (load order) matters
°
Physical placement of DCPMM modules along with the DRAM DIMMs matters. If the load order of these
DRAMs/DCPMMs are wrong, the system might not boot. See “How to Congure the System HW” section
below for more info about load order.
• OS Revision matters
°
DCPMM congurations require a Persistent Memory (PMEM) Aware OS revision and updated OS patches.
See the System Requirements section below for a list of supported OSes and minimum revision levels.
• DCPMM has embedded rmware
°
Unlike DRAM memory, DCPMM has rmware and might need to be updated over the life of the module.
It is recommended that anytime the BIOS (UEFI Firmware) is updated, the BIOS release notes should
be checked to see if the rmware on the DCPMM module(s) need to be updated as well. See below
for instructions on how to update the rmware.
• Here we’ll introduce some organizing terms relevant to Storage Mode and App Direct Modes that will be useful
in the discussions that follow. These terms do not apply to Memory Mode.
°
The DCPMM modules located in the memory slots for a specic processor are called a DCPMM set.
CONTENTS & NAVIGATION
1
Introduction
5
DCPMM Security
Overview
System Requirements
6
System Setup Overview
8
Appendices