PowerEdge: Endless Reboot Loop After Changing 'SST-Performance Profile' and 'Number of Cores per Processor' BIOS Settings
Summary: PowerEdge 16G platform is stuck in an endless loop, continuously restarting during the POST at the "configure memory…" stage.
This article applies to
This article does not apply to
This article is not tied to any specific product.
Not all product versions are identified in this article.
Symptoms
After modifying the BIOS options for "SST-Performance Profile" and "Number of Cores per Processor" together, the system is stuck in an endless loop, repeatedly restarting during the POST at the "configure memory" stage.
Cause
The combination of "SST-Performance Profile" and "Number of Cores per Processor" does not work together.
Resolution
Avoid modifying "SST-Performance Profile" and "Number of Cores per Processor" simultaneously.
If the system is already caught in an endless reboot loop, perform an NVRAM clear to break the cycle. For instructions on how to clear NVRAM by jumpers, see the video How to Clear NVRAM via Jumpers for PowerEdge R660.
The upcoming Dell BIOS September Block release 2.3.x introduces improvements:
- In the BIOS SETUP, users are now prevented from modifying "Number of Cores Per Processor" and "SST-Performance Profile" simultaneously. "Number of Cores Per Processor" will be blocked immediately after "SST-Performance Profile" is changed to OP2 or OP3. Conversely, "SST-Performance Profile" will be blocked immediately after "Number of Cores Per Processor" is set to a value other than "All."
In the iDRAC WebGUI, under Configuration -> BIOS Settings, These restrictions only take effect after a system reboot.
Modifying both settings simultaneously is still possible, but upon reboot, the following error message is logged in the Lifecycle Controller (LC), and the system does not enter an endless reboot loop:
PR16 Some of the configuration values could not be applied to device: PowerEdge R660(System BIOS Setup)
Affected Products
PowerEdge R660, PowerEdge R660xs, PowerEdge R760, PowerEdge R760XA, PowerEdge R760xd2, PowerEdge R760xs, PowerEdge R860, PowerEdge R960, PowerEdge T560Products
PowerEdge C6615, PowerEdge C6620, PowerEdge HS5610, PowerEdge HS5620, PowerEdge MX760c, PowerEdge T360, PowerEdge XE8640, PowerEdge XE9640, PowerEdge XE9680, PowerFlex appliance R660, PowerFlex appliance R760Article Properties
Article Number: 000226735
Article Type: Solution
Last Modified: 05 May 2025
Version: 2
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.