AMD 30925 manual Calculating System Power Consumption, Power Worksheet 1-Component Power

Builder’s Guide for AMD Opteron™ Processor-Based	30925 Rev. 3.04 February 2004
Servers and Workstations

In order to have a reliable and cost-effective system, system builders should calculate the power requirements for the intended configuration.

Note: System builders should refer to the motherboard manual to check the type of power connector and type of power supply the motherboard uses. The motherboard, power supply, and case must be mechanically and electrically compatible.

5.2.2Calculating System Power Consumption

The total combined wattage for the system configuration must be less than the output of the power supply used. Overall current usage limitation on the power supply should not exceed a combined system power output for the +5-V and +3.3-V outputs.

Use the power worksheets given in Table 1 on page 32 and Table 2 on page 33 to calculate the system power consumption. For current and voltage requirements of add-in boards and peripherals, refer to your vendor’s documents. The current draw on each voltage tap should be included with the documentation from the motherboard vendor.

In Power Worksheet 1—Component Power list the peak current for each board and device applicable in the appropriate voltage level column. Add the currents in each column, then go to Power Worksheet 2—Total Watts.

Table 1. Power Worksheet 1—Component Power

Device	Item	Maximum Current at Each Voltage Level
	Qty
		+3.3 V	+5 V	+12 V	–12 V	5 VSB

Motherboard w/on-board devices

System fan

Processor fan

Memory module

AGP VGA card

PCI modem card

PCI sound card

PCI NIC card

PCI SCSI card

Other PCI card/Bus card

PCI RAID card

IDE hard drive

SCSI hard drive

32 Hardware Considerations Chapter 5