consumption. Depending on the actual power requirements, the iDRAC power envelope may change over time. iDRACrequests a power step-up only if the servers are fully consuming the allocated power.Under heavy load the performance of the server’s processors may be degraded to ensure power consumption stayslower than the user-configuredSystem Input Power Cap.The PowerEdge M1000e enclosure can supply enough power for peak performance of most server configurations, butmany available server configurations do not consume the maximum power that the enclosure can supply. To help datacenters provision power for their enclosures, the M1000e allows you to specify aSystem Input Power Cap to ensure thatthe overall chassis AC power draw stays under a given threshold. CMC first ensures enough power is available to runthe fans, IO Modules, iKVM (if present), and CMC itself. This power allocation is called theInput Power Allocated toChassis Infrastructure. Following Chassis Infrastructure, the servers in an enclosure are powered up. Any attempt to setaSystem Input Power Cap less than the actual consumption fails.If necessary for the total power budget to stay below the value of theSystem Input Power Cap, CMC allocates servers avalue less than their maximum requested power. Servers are allocated power based on theirServer Priority setting, withhigher priority servers getting maximum power, priority 2 servers getting power after priority 1 servers, and so on. Lowerpriority servers may get less power than priority 1 servers based onSystem Input Max Power Capacity and the user-configured setting ofSystem Input Power Cap.Configuration changes, such as an additional server in the chassis, may require theSystem Input Power Cap to beincreased. Power needs in a modular enclosure also increase when thermal conditions change and the fans arerequired to run at higher speed, which causes them to consume additional power. Insertion of I/O modules and iKVMalso increases the power needs of the modular enclosure. A fairly small amount of power is consumed by servers evenwhen they are powered down to keep the management controller powered up.Additional servers can be powered up in the modular enclosure only if sufficient power is available. TheSystem InputPower Cap can be increased any time up to a maximum value of 16685 watts to allow the power up of additional servers.Changes in the modular enclosure that reduce the power allocation are:• Server power off• Server• I/O module• iKVM removal• Transition of the chassis to a powered off stateYou can reconfigure theSystem Input Power Cap when chassis is either ON or OFF.Server Slot Power Priority SettingsCMC allows you to set a power priority for each of the sixteen server slots in an enclosure. The priority settings are 1(highest) through 9 (lowest). These settings are assigned to slots in the chassis, and the slot's priority is inherited by anyserver inserted in that slot. CMC uses slot priority to preferentially budget power to the highest priority servers in theenclosure.According to the default server slot priority setting, power is equally apportioned to all slots. Changing the slot prioritiesallows administrators to prioritize the servers that are given preference for power allocations. If the more critical servermodules are left at their default slot priority of 1, and the less critical server modules are changed to lower priority valueof 2 or higher, the priority 1 server modules is powered on first. These higher priority servers get their maximum powerallocation, while lower priority servers may be not be allocated enough power to run at their maximum performance orthey may not even power on at all, depending on how low the system input power cap is set and the server powerrequirements.If an administrator manually powers on the low priority server modules before the higher priority ones, then the lowpriority server modules are the first modules to have their power allocation lowered down to the minimum value, in order187
