Lenovo ThinkSystem SR950 Setup Manual page 218

• Remove and install only one PHM at a time. If the system board supports multiple processors, install the
PHMs starting with the first processor socket.
• Do not allow the thermal grease on the processor or heat sink to come in contact with anything. Contact
with any surface can compromise the thermal grease, rendering it ineffective. Thermal grease can damage
components, such as electrical connectors in the processor socket. Do not remove the grease cover from
a heat sink until you are instructed to do so.
• To ensure the best performance, check the manufacturing date on the new heat sink and make sure it
does not exceed 2 years. Otherwise, wipe off the existing thermal grease and apply the new grease onto it
for optimal thermal performance.
Notes:
• PHMs are keyed for the socket where they can be installed and for their orientation in the socket.
• See
https://static.lenovo.com/us/en/serverproven/index.shtml
server. All processors on the system board must have the same speed, number of cores, and frequency.
• Before you install a new PHM or replacement processor, update your system firmware to the latest level.
See "Update the firmware" on page 256.
• Installing an additional PHM can change the memory requirements for your system. See "Install a memory
module" on page 216 for a list of processor-to-memory relationships.
• Optional devices available for your system might have specific processor requirements. See the
documentation that comes with the optional device for information.
Before installing a PHM:
Note: The PHM for your system might be different than the PHM shown in the illustrations.
1. Remove the front cover. See "Remove the front cover" on page 322.
2. Remove the compute tray where the system board is installed. See "Remove a compute tray" on page
305.
3. If you are installing a PHM in the lower system board, remove the upper system board or system board
filler. See "Remove a system board" on page 309.
ThinkSystem SR950 Setup Guide
214
for a list of processors supported for your