HP ProLiant DL380 Generation 3 Server High-Density Deployment 
 
14 
Input Power 
Budget Derating 
 
If a deployment plan limits the future expansion beyond certain configuration options, adjustments 
can be made to the expected input current and thermal requirements of the servers. 
To derate the input power, start with the minimum configuration 1 from Table 3. Add the typical 
power of the components included in the desired system configuration to calculate the derated power 
budget. Typical input powers for various components are listed in Table 5. 
Example 
Assuming the desired server configuration is as follows, use Table 7 to calculate the derated power 
budget using the typical power from Table 5. 
Processors: 2 x 2.4 GHz 
Memory: 4 x 512 MB 
Storage: 2 x 18.2 GB  
Table 7.  Example of Derating Worksheet 
1.  Start with the maximum rated input power for the base configuration  
(1 processor, 2 DIMMs, 0 hard drives) 
207 W 
2.  Add the typical power for the second processor  +40 W 
3.  Add the typical power for the additional memory  +4.8 W (2.4 W per DIMM) 
4.  Add the typical power for the additional storage 
  Typical power for the desired configuration 
+ 38 W (19 per hard drive) 
= 290 W 
5.  Calculate the thermal dissipation 
  Thermal dissipation for the desired configuration (in BTUs) 
× 3.41 
989 BTUs/hour 
 
Therefore, the new power budget for this configuration is 290 W (compared to the rated 565 W), 
and the thermal dissipation is approximately 989 BTUs/hour (compared to the rated 1927 
BTUs/hour). 
The rated input power for the server power supply is 565 W. Therefore, the power budget for a 
maximum configuration is 565 W, and the thermal dissipation will be approximately (565*3.41=) 
1927 BTUs/hour. 
This derated input power budget significantly reduces the power and thermal requirements for highly 
populated racks, which reduces the number of PDUs for certain configurations. Fewer PDUs decrease 
deployment time and lower costs. Costs for the facility electrical plumbing, data center floor 
ventilation, and facility air conditioning installation can also be reduced. 
IMPORTANT:   HP strongly recommends verifying that the derated power budget satisfies all the 
installation requirements, including future upgrade plans.