HP DL320 hp ProLiant DL320 generation 2 server high-density deployment - Page 7

hp ProLiant DL320 generation 2 server high-density deployment technical white paper 7 Table 4. Example Derating Worksheet Maximum Rated Input Power for the Base Configuration 1. Add the typical power for the additional memory. 2. Add the typical power for the second HDD. 3. Add the typical power for the PCI card Typical power for the desired configuration 4. Calculate the thermal dissipation. Thermal dissipation for the desired configuration (in BTUs) Typical Power 2 W per DIMM 5 W 15W 169 W ×3.41 576 BTUs/hour 143 W Therefore, the new power budget for this configuration is 169 W (compared to the rated 277 W), and the thermal dissipation is approximately 576 BTUs/hour (compared to the rated 945 BTUs/hour). The rated input power for the server power supply is 277 W. Therefore, the power budget for a maximum configuration is 231 W, and the thermal dissipation will be approximately 231 * 3.41 = 788 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 decreases deployment time and lowers 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. input power budget allocation This section explains how to allocate the input power budget for each server. This method can be used when a PDU supports a known number of servers. It is important to verify that the calculated power budget allocation will be sufficient to support the worst-case server configurations that are to be deployed. The allocated input power for each server is calculated by multiplying the allocated input current for each server by the line voltage. Allocated Input Power = Allocated Input Current * Input Line Voltage Example Assume a high-voltage PDU rated at 24 A is to support 21 servers. Each server can be allocated 1.143 A. If the line voltage is assumed to be at 208 V, then the allocated input power budget for each server will be (1.143*208) = 238 W. Since the input power budget of 238 W satisfies the fully configured system measured input power of 185 W (as shown in Table 3), 21 servers may be supported by a 24 A high-voltage PDU. That means only two of these PDUs are needed to support 42 servers in a 42U rack.