Builder’s Guide for AMD Athlon™ 64 Processor-Based
Desktops and Workstations
31684 Rev.
3.00 September
2004
4.2
Power Supply Guidelines
AMD Athlon 64 processor-based motherboards may be designed to leverage industry standard
power supplies. The selection of the proper system-power supply is a critical element to the
success of the finished system. For best results, a system builder should always contact the
motherboard, power supply, and chassis suppliers or vendors to verify that each of the chosen
components supports the desired system configuration, and a system builder should verify that
support through internal testing and validation.
4.2.1
Desktop and Workstation Platform Power Supplies
Depending on the motherboard vendors’ design requirements, a desktop or workstation platform
can use either an ATX 12-V power supply, or an EPS12V. The motherboard design can use one or
two power connectors. Usually a separate power connector is used to provide power for the I/O
components. It is important that you confirm with the motherboard manufacturer the exact
connector requirements.
Note:
It is imperative that system builders ensure that the power supply of choice and the selected
chassis are mechanically compatible.
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.
4.2.2
Calculating 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
on page 27 and Table 2 on page 28 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.
Table 1
Power Worksheet 1—Component Power
In
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
26 Hardware
Considerations
Chapter 4
