Lenovo ThinkStation P920, ThinkStation P720 Memory Configurations [en, ar, bg, cs, da, de, el, es, es, fi, fr, he, hr, hu, it, ja, ko, nb, nl, pl, pt, pt, ro, ru, sh, sk, sl, sv, th, tr, uk, zc, zh]

LENOVO T HINKSTATION

P920 AND P720 MEMORY
CONFIGURATOR

Contents

OVERVIEW
SECTION 1 – PLATFORM MEMORY ARCHITECTURE
SECTION 2 – P920 MEMORY CONFIGURATIONS
SECTION 3 – P720 MEMORY CONFIGURATIONS
SECTION 4 – DOCUMENT REVISION HISTORY

Overview

The purpose of this document is to provide guidance for users on how to optimally
configure the system memory in the ThinkStation P920 and P720 platforms in
order to provide the best performance.

Section 1 – Platform Memory Architecture

The launch of the Intel® Purely platform has brought with it some exciting
changes to the system architecture for memory as compared to previous
workstation platforms. Newly added features such as support for 6 channels of
memory (per CPU) and a higher top supported memory bus speed combine to
provide users with significantly improved memory performance in their
workstations. Both the ThinkStation P920 and ThinkStation P720 have been
designed to take advantage of these new architecture enhancements to the
memory subsystem.

1

1

CPU 2

CPU 1

CPU1 – DIMM 2

CPU1 – DIMM 6

CPU1 – DIMM 4

CPU1 – DIMM 8

CPU1 – DIMM 7

CPU1 – DIMM 3

CPU1 – DIMM 5

CPU1 – DIMM 1

CPU2 – DIMM 1

CPU2 – DIMM 5

CPU2 – DIMM 3

CPU2 – DIMM 7

CPU2 – DIMM 8

CPU2 – DIMM 4

CPU2 – DIMM 6

CPU2 – DIMM 2

Section 2 – P920 Memory Configurations

The ThinkStation P920 is Lenovo’s largest and most powerful workstation built to

date. The dual CPU design has 16 total DIMM slots (8 per CPU) with a top
supported memory bus speed of 2666MHz
slots, the P920 can take full advantage of all 6 channels of memory support offered
by the new Intel® Xeon® E5 Skylake CPUs. Figure 1 below shows a visual
reference of the DIMM slot layout for the P920 platform.

Figure 1 - P920 Motherboard DIMM Layout

.

With each CPU supporting 8 DIMM

Actual memory bus speed is determined by the CPU(s) selected.

The following guidelines are recommended by Lenovo for obtaining the best
memory bandwidth from your P920 when filling DIMM slots:

 In single CPU configurations, only DIMM slots for CPU1 can be

utilized. For dual CPU configurations, all DIMM slots can be utilized.

 In dual CPU configurations, it is optimal to balance memory across

CPUs. This applies to both DIMM quantity and capacity. While the
system will function with unbalanced DIMMs, overall memory
performance could be affected.

 For best memory bandwidth performance, Lenovo recommends

optimizing the overall memory configuration to use 6 DIMMs per
CPU. DIMMS A1 and D1 (for each CPU) can be used where overall
memory capacity is prioritized over memory bandwidth.

 Once DIMM quantity and DIMM capacity have been balanced across

CPUs (if necessary), users should follow the recommended fill order
for each CPU found in Figure 2. Largest capacity DIMMs should be
installed first if using mixed DIMM capacities.

# of DIMMs per CPU

DIMM slots used for each CPU

1 DIMM

DIMM 3

2 DIMMs

DIMM 3, DIMM 5

3 DIMMs

DIMM 1, DIMM 3, DIMM 5

4 DIMMs

DIMM 3, DIMM 4, DIMM 5, DIMM 6

5 DIMMs2

Not Recommended

6 DIMMs

DIMM 1, DIMM 2, DIMM 3, DIMM 4, DIMM 5, DIMM 6

7 DIMMs2

Not Recommended

8 DIMMs3

DIMM 1, DIMM 2, DIMM 3, DIMM 4, DIMM 5,
DIMM 6, DIMM 7, DIMM 8

2

3

Figure 2 shows the recommended DIMM slot fill order for each CPU installed in the
system.

Figure 2 – P920 DIMM Slot Fill Order Recommendations

Note: Memory configurations using 5 DIMMs or 7 DIMMs per CPU are not recommended as they
are unbalanced configurations that could result in memory performance degradation.

- 5 DIMM per CPU and 7 DIMM per CPU configurations will function, but should be avoided as

they present an unbalanced load to the CPU that could result in memory bandwidth degradation.

- 8 DIMM per CPU configurations represent an unbalanced load to the CPU, but these
configurations can be used where overall memory capacity takes priority over bandwidth. For
maximum memory bandwidth, Lenovo recommend optimizing on 6 DIMMs per CPU if possible.

4

CPU 1

CPU 2

CPU2 – DIMM 3

CPU2 – DIMM 5

CPU2 – DIMM 1

CPU2 – DIMM 2

CPU2 – DIMM 6

CPU2 – DIMM 4

CPU1 – DIMM 1

CPU1 – DIMM 5

CPU1 – DIMM 3

CPU1 – DIMM 4

CPU1 – DIMM 6

CPU1 – DIMM 2

Section 3 – P720 Memory Configurations

TCPOUhe ThinkStation P720 is the latest compact dual processor workstation.
Like the P920, it also features a dual CPU design. But in an effort to maintain the
smaller chassis size the P720 utilizes a 12 DIMM slot design (6 DIMMs per CPU).
This allows P720 to take full advantage of all 6 memory channels offered by the
new Intel® Xeon® E5 Skylake CPUs in a single DIMM per channel configuration
and also support the highest memory bus speed of 2666MHz4. Figure 3 shows a
visual representation of the DIMM slot layout for the P720 platform.

Figure 3 - P720 Motherboard DIMM Slot Layout

Actual memory bus speed is determined by the CPU(s) selected.

# of DIMMs per CPU

DIMM slots used for each CPU

1 DIMM

DIMM 3

2 DIMMs

DIMM 3, DIMM 5

3 DIMMs

DIMM 1, DIMM 3, DIMM 5

4 DIMMs

DIMM 3, DIMM 4, DIMM 5, DIMM 6

5 DIMMs5

Not Recommended

6 DIMMs

DIMM 1, DIMM 2, DIMM 3, DIMM 4,
DIMM 5, DIMM 6

5

The following guidelines are recommended by Lenovo for obtaining the best
memory bandwidth from your P720 when filling DIMM slots:

 In single CPU configurations, only DIMM slots for CPU1 can be

utilized. For dual CPU configurations, all DIMM slots can be utilized.

 In dual CPU configurations, it is optimal to balance memory across

CPUs. This applies to both DIMM quantity and capacity. While the
system will function with unbalanced DIMMs, overall memory
performance could be affected.

 For best memory bandwidth performance, Lenovo recommends

optimizing the overall memory configuration to use 6 DIMMs per
CPU.

 Once DIMM quantity and DIMM capacity have been balanced across

CPUs (if necessary), users should follow the recommended fill order
for each CPU found in Figure 4. Largest capacity DIMMs should be
installed first if using mixed DIMM capacities.

Figure 4 shows the recommended DIMM slot fill order for each CPU installed in the
system.

Figure 4 - P720 DIMM Slot Fill Order Recommendations

Note: Memory configurations using 5 DIMMs per CPU are not recommended as they are
unbalanced configurations that could result in memory performance degradation.

- 5 DIMM per CPU configurations will function, but should be avoided as they present an
unbalanced load to the CPU that could result in memory bandwidth degradation.

Version

Date

Author

Changes/Updates

1.0

11/8/2017

Cory Chapman

Initial launch release

Section 4 – Document Revision History