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Choosing between Lenovo ThinkSystem SR850 and SR950


16 Aug 2017
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6 pages, 289 KB


Lenovo has two new ThinkSystem 4-socket rack servers. The ThinkSystem SR850 is a 2U, 4-socket system and the ThinkSystem SR950 is a 4U system capable of 4 or 8 sockets. Several factors need to be considered when choosing which system that best fits your 4-socket requirements.


Lenovo has two ThinkSystem 4-socket capable rack servers. Which one to choose for your 4-socket workloads might not be an obvious decision. This article helps explain the similarities and differences of the ThinkSystem SR850 and SR950 to help with this decision.

SR850 and SR950 overview

The Lenovo SR850 and SR950 are new 4-socket-capable rack servers with strong performance, memory and storage capabilities. Both servers support demanding workloads such as data analytics, large virtualization and enterprise databases

The Lenovo SR850 is a 2U Rack server capable of up to 4 processors and 48 DIMM. The SR850 features a CPU and Memory mezzanine board. Clients have flexibility to configure from 2 Socket 24 DIMM to 4S 48 DIMMs. The SR850 delivers exceptional price/ performance in a dense 2U rack server.

Lenovo ThinkSystem SR850
Figure 1. Lenovo ThinkSystem SR850

The Lenovo SR950 is a 4U Rack server capable of up to 8 processors and 96 DIMMs. The SR950 features a modular system with all components accessible via the front or rear of the server. Clients can configure multiple configurations from 2 sockets and 24 DIMM to 8 sockets and 96 DIMMs. The SR950 delivers the highest performance, greatest I/O capabilities and the most NVMe support.

Lenovo ThinkSystem SR950
Figure 2. Lenovo ThinkSystem SR950

Common features and capabilities

The SR850 and SR950 share many features and capabilities.

Table 1. Common features
Feature Feature Description Customer Benefit
XClarity Single Management interface across portfolio Easy to learn and manage - apply cross Lenovo portfolio.
Options Shared HDD, SSD, PSU, RAID cards, PCIe, etc Less option parts for clients and business partner to manage and stock
M.2 M.2 embedded OS Allows for integrated boot media. M.2 provides lower cost, better performance and higher reliability than USB, SD card
NIC options Modular LOM choices for customization (LOM, ML2, PCIe) Lower cost I/O and greater choice. Only purchase what you need
Direct NVMe Direct NVMe connector on the CPU board Direct NVMe saves PCIe slots and lower cost of ownership compare to the NVMe switch card solution.
2S to 4S Upgrade Simple 2S to 4S upgrade within the same system Grow the system as your application needs increase. Only pay for what you need.
RAS Intel Run Sure and Predictive Failure Analysis (PFA) Provides outstanding system availability and uninterrupted application performance
Optional Front LCD Front diagnostic LCD panel display Used to quickly obtain system status, firmware levels, network information, and health information about the system.

SR850 and SR950 Differences

If you need an 8 socket configuration or the ability to upgrade to the 8 socket configuration in the future, the SR950 is your only choice. If you only need a 4-socket server, you have a choice between the SR850 and SR950. Below are the major differences to help you select between the SR850 and SR950 in a 4-socket configuration.

Table 2. Differences between the SR850 and SR950
Feature/ Capability SR850 (4S configuration) SR950 (4S configuration)
Size 2U rack mount 4U rack mount
Sockets 2 to 4 sockets 2 to 4 sockets with ability to upgrade to 8 sockets in future
Storage Bays Up to 16 2.5” bays Up to 24 2.5” bays
Memory Up to 48 DIMM slots and supporting 128GB DIMMs post launch Up to 48 DIMM slots and supporting 128GB DIMM at launch
NVMe Up to 8 NVMe drives Up to 12 NVMe drives
Rear Networking slots Up to 10 (PCIe, LOM and ML2) Up to 15 (PCIe, LOM and ML2)
High Bandwidth Networking Up to 3 (x16) adapter slots in 4S Up to 7 (x16) adapter slots in 4S
Intel Processor Support Strong selection of 51xx, 61xx and 81xx CPUs up to 165W Every available 51xx, 61xx and 81xx CPU including 205W CPUs
Intel 61xx and 81xx CPU Performance Less performance on average than SR950 (equal performance if using 51xx CPUs) Maximum system performance
Power Supply 2 power supply bays including 750W PSU 4 power supply bays
SAP HANA Certified for SAP HANA TDI Certified SAP HANA Appliance
Cost Lower base cost Higher base cost

About the author

Randall Lundin is a Senior Product Manager in the Lenovo Infrastructure Solution Group. He is responsible for planning and managing ThinkSystem servers. Randall has also authored and contributed to numerous Lenovo Press publications on ThinkSystem products.

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