Introduction

This document provides additional design details to supplement multiple desktop internal power supply form factors design guides. This addendum focuses on the power requirements needed by the processor’s Voltage Regulator (VR) usually specified as 12V2 in a desktop power supply design. Different generations of Intel processors have different power consumption needs and therefore the power supply needs to be able provide the power to the processor’s VR.

Intel processors specify their power consumption in multiple levels. This document will translate the general processor power needs and covert them to what a power supply will need to provide. Generic power levels of Intel processors:

• Thermal Design Power (TDP): Power level defined as the long-term power consumption limit of a processor that the processors’ thermal solution will need to provide cooling for. This can also be referenced as Power Level 1 (PL1)
• Power Level 2 (PL2): Intel® Turbo Boost Technology will increase the ratio of application power towards TDP and allows an increase in power above TDP as high as PL2 for short periods of time.
• The period of time that a processor can stay above the TDP level and at PL2 power levels is usually less than 1 minute. This time can vary with processors and system level designs. When power supplies need to provide power beyond a few seconds that is considered a long time and therefore the PL2 power level has been defined as the “Continuous Current” level in the PSU Design Guide.
Note:Intel® Turbo Boost Technology may not be available on all SKUs.
• Power Level 4 (PL4): Intel defines a Max Power (Current) consumption for each of its processors. This power level can only last a short amount of time, normally ≤ 10 ms. The PSU Design Guide specifies this value as Peak Current
• Power Level 4 Application (PL4.app): PL4.app is less than PL4 and is the electrical power drawn by the CPU representing a typical user realistic application(s) scenario at an all core turbo frequency. PL4.app represents worst case power with real world workloads. PL4.app will sustain for ≤ 10 ms.

Intel’s PSU Test Plan recommends testing the peak current value as “Peak Current FVM” for CPUs that have this value. If “Peak Current FVM” value is not provided, then Intel’s Test plan will recommend using the “Peak Current” value.

The document is an addendum to the following the documents:

• Multi Rail Desktop Power Supply Design Guide
• Desktop Platform Form Factors Power Supply Design Guide (#336521)
• Single Rail Desktop Power Supply Design Guide
• Single Rail Power Supply Design Guide – ATX12VO (12V Only) (#613768)