Lenovo ThinkSystem firmware is Unified Extensible Firmware Interface (UEFI) 2.5 compliant. UEFI 
replaces BIOS and defines a standard interface between the operating system, platform firmware, and 
external devices. 
Lenovo ThinkSystem servers are capable of booting UEFI-compliant operating systems, BIOS-based 
operating systems, and BIOS-based adapters as well as UEFI-compliant adapters.
Note: The server does not support DOS (Disk Operating System).
•  Large system-memory capacity
The server supports registered dual-inline memory modules (RDIMMs) and load-reduced DIMMs 
(LRDIMMs) with error correcting code (ECC). The server supports up to a maximum system memory of 
384 GB (using RDIMMs) or 768 GB (using LRDIMMs). For more information, see “Specifications” on page 
5.
•  Integrated Trusted Platform Module (TPM)
This integrated security chip performs cryptographic functions and stores private and public secure keys. 
It provides the hardware support for the Trusted Computing Group (TCG) specification. You can 
download the software to support the TCG specification.
Trusted Platform Module (TPM) has two versions - TPM 1.2 and TPM 2.0. You can change the TPM 
version from 1.2 to 2.0 and back again.
For more information on TPM configurations, see “Enable TPM/TCM” in the Maintenance Manual.
Note: For customers in Chinese Mainland, a Lenovo-qualified TPM 2.0 adapter or a Trusted 
Cryptographic Module (TCM) adapter (sometimes called a daughter card) may be pre-installed.
•  Large data-storage capacity and hot-swap capability 
The hot-swap server models support up to twelve 3.5-inch hot-swap SAS/SATA drives or sixteen 2.5-inch 
hot-swap SAS/SATA drives. The simple-swap server models support a maximum of eight 3.5-inch simple- 
swap SATA drives.
With the hot-swap feature, you can add, remove, or replace hard disk drives without turning off the server.
•  Mobile access to Lenovo Service Information website 
The server provides a QR code on the system service label, which is on the cover of the server, that you 
can scan using a QR code reader and scanner with a mobile device to get quick access to the Lenovo 
Service Information website. The Lenovo Service Information website provides additional information for 
parts installation, replacement videos, and error codes for server support. 
•  Redundant networking connection
The Lenovo XClarity Controller provides failover capability to a redundant Ethernet connection with the 
applicable application installed. If a problem occurs with the primary Ethernet connection, all Ethernet 
traffic that is associated with the primary connection is automatically switched to the optional redundant 
Ethernet connection. If the applicable device drivers are installed, this switching occurs without data loss 
and without user intervention.
•  Redundant cooling and optional power capabilities 
The server supports a maximum of two 550-watt or 750-watt hot-swap power supplies and four non hot- 
swap fans, which provide redundancy for a typical configuration. The redundant cooling by the fans in the 
server enables continued operation if one of the fans fails.  
Note: You cannot mix 550-watt and 750-watt power supplies in the server.
4
ThinkSystem SR550 Setup Guide