Technical White Paper Custom Cooling Fan Options for Dell EMC PowerEdge Servers Updated for the 14th Generation of Dell EMC Servers and iDRAC9 Abstract Dell PowerEdge server fan control customization options and their potential use cases.
Revisions Revisions Date Description October 2019 Rev 1.0 – Updated release for iDRAC9 based Dell EMC Servers Acknowledgments This paper was produced by the following: Authors: Hasnain Shabbir, Carlos Henry, Danny Whittington, and Jon Brown Support: Dell EMC Server Thermal Controls Team The information in this publication is provided “as is.” Dell Inc.
Table of contents Table of contents Revisions............................................................................................................................................................................. 2 Acknowledgments ............................................................................................................................................................... 2 Table of contents ..............................................................................................
Executive summary Executive summary Sometimes, it is desirable to customize server cooling. For example, installing a third-party PCIe card could require more cooling beyond that which Dell EMC controls have provisioned. In other cases, the exhaust temperature of the server may be too high for a switch that is mounted behind the server. For these reasons, Dell EMC provides the fan control customization options that are discussed in this paper.
Introduction 1 Introduction Dell PowerEdge servers include proprietary thermal controls that automatically manage server component temperatures. Dell PowerEdge controls use sensor monitoring and knowledge of the specific hardware that is installed on the system to minimize fan speeds, airflow, and power consumption without sacrificing component reliability. This white paper describes fan control customization options and suggests some potential use cases.
System Thermal Profile settings 2 System Thermal Profile settings System Thermal Profile settings can be changed based on the need to maximize performance or power efficiency. • Default Thermal Profile Settings: - • Maximum Performance: - • Optimized for lowest system power consumption based on optimum fan power state Generally, lower fan speeds at idle and stress loads Sound Cap: - 2.
System Thermal Profile settings This option is used to provide additional cooling to custom configurations to the customer. The thermal algorithm maintains enough cooling without application of such offsets. The common use case is to add additional cooling to custom PCIe adapter cards, or to reduce the system exhaust temperature for platforms that do not support these specific customizations. Illustration of how the fan speed offset increases the fan speed above the baseline (green line) 2.
System Thermal Profile settings How the Minimum Fan Speed setting creates a fan speed floor, or lower bound Other subsystems within the server, such as the CPU, can require higher fan speeds than the MFS or automatic baseline. Such requirements can occur during moderate to high use of that computing subsystem. 2.3 8 Combined Settings – Fan offset and MFS Fan offset and MFS can be used together to achieve a combined effect.
System Thermal Profile settings How options can be combined with MFS and Offset set simultaneously If Low Offset and 40% MFS are applied, Fan Speed follows the red dotted line based on Inlet Ambient. 2.4 Maximum exhaust temperature limit This option allows the system fans speeds to be regulated to prevent the system exhaust air temperature from exceeding the chosen threshold.
System Thermal Profile settings How airflow increases to maintain an exhaust temperature limit. Options go all the way to 40°C.
Customizing PCIe card cooling 3 11 Customizing PCIe card cooling In 14th Generation servers, Dell has implemented an industry-leading solution for PCIe cooling that enables the user better to understand the nature and amount of cooling to their PCIe cards. Since this topic is complex, see the white paper titled “PCIe Card Cooling with Dell PowerEdge Servers - Updates based on 14th Generation of Servers (iDRAC9)” dedicated to this subject.
Accessing thermal settings 4 Accessing thermal settings Custom fan speed options described earlier can be applied on many different customer-facing interfaces such as iDRAC GUI, BIOS setup (F2), and RACADM. Figure 5 illustrates user interaction with server using various interfaces.
Accessing thermal settings The following is a summary of customer interfaces and typical reasons for using the interfaces for customization, in this case, fan speed customization: • iDRAC UI - Web-browser based Requires a network connection UI-based and easy to navigate No reboot required NOTE: Alternate access using a USB A-A cable is also possible. • Human Interface Infrastructure (HII) browser - • • • 4.
Accessing thermal settings User cooling options section Setting Max Exhaust Temperature Limit 14 Custom Cooling Fan Options for Dell EMC PowerEdge Servers
Accessing thermal settings Setting Fan Speed Offset Setting Minimum Fan Speed (MFS) 15 Custom Cooling Fan Options for Dell EMC PowerEdge Servers
Accessing thermal settings 4.1.1 System Thermal Profile Settings In addition to the custom cooling options, the System Thermal Profile can be changed based on the desire to maximize performance or power efficiency. The Thermal Profile determines the settings that are used for the “Automatic Baseline” described in the previous sections. Setting thermal profile 4.2 Custom Fan Speed Options using iDRAC WebGUI iDRAC WebGUI is a UI-based web management interface.
Accessing thermal settings iDRAC dashboard view iDRAC cooling page Then select Cooling→ Configure Cooling.
Accessing thermal settings Configure cooling option Make your selections under the Cooling Configuration option: iDRAC custom cooling options Each of the options that are described earlier can be toggled independently and set at the same time. For example, low Fan Speed Offset, and Exhaust of 50°C and Minimum Fan Speed of 20% can be set concurrently. The algorithm calculates the appropriate fan speed that meets all the customization requests.
Accessing thermal settings Setting multiple custom control options 4.3 Custom fan speed options using RACADM After logging into iDRAC, run racadm get system.thermalsettings to display the current settings. The results may vary depending on the iDRAC version used. It is recommended that you are working with at least 3.30.30.30 or newer release. Here is an example of the command and its results: get system.thermalsettings [Key=system.Embedded.1#ThermalSettings.
Accessing thermal settings The following table can be used as a guide to configure these settings using the racadm system.thermalsettings command: Configure settings using racadm system.thermalsettings command Object Description Usage Example AirExhaustTemp • Max Air Exhaust Temperature limit setting. • Set Exhaust Temperature Limit to any one value (platform dependent), where 0,1,2,3,4 and 255 correspond to 40,45,50,55,60°C and 70°C (default).
Accessing thermal settings FanSpeedHighOffsetVal FanSpeedLowOffsetVal FanSpeedMaxOffsetVal FanSpeedMediumOffset Val 21 • Getting this variable Values reads the fan speed from 0-100 offset value in %PWM for High Fan Speed Offset setting. • This value is platform-dependent. • Use FanSpeedOffset to set this value using index value 1. racadm get system.thermalsettings FanSpeedHighOffsetVal • Getting this variable Values reads the fan speed from 0-100 offset value in %PWM for Low Fan Speed Offset setting.
Accessing thermal settings FanSpeedOffsetl MFSMaximumLimit MFSMinimumLimit MinimumFanSpeed 22 • Using this with “get” reports the existing Fan Speed Offset setting. • Using this with “set” allows setting the wanted fan speed offset value. • The index governs what offset is applied and FanSpeed…Val variables (defined earlier) are the values at which the offsets are applied.
Accessing thermal settings ThermalProfile • Selection for Thermal Profile • Allows system profile to be set at preferred setting for thermal behavior that is associated with the profile. 0-Default Thermal Profile, 1Maximum performanc e, 2Minimum Power, 3Sound Cap (on supported platforms). Example using get: racadm get system.thermalsettings.ThermalP rofile Reports the current ThermalProfile setting Example using set: racadm set system.thermalsettings.
