Intel® FPGA Power and Thermal Calculator User Guide

ID 683445
Date 10/04/2021
Public

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4.2. Intel® FPGA PTC - Common Page Elements

The Intel® FPGA Power and Thermal Calculator ( Intel® FPGA PTC) is divided into multiple pages, each allowing entry of a subset of FPGA resources. Some elements are common to more than one page.
Note: If you want to resize columns within a page, that is most easily done with the Intel FPGA PTC window size maximized. You can also resize all columns on all pages by selecting View > Resize All Columns, or by pressing F5 on your keyboard.

Recalculate mode

The Recalculate mode pulldown is available at the top-left corner of the PTC, regardless of which page is displayed. The available settings are Automatic and Manual:

  • Automatic: In Automatic mode, the system automatically recalculates all field values whenever you modify an input value. Automatic is the default mode.
  • Manual: In Manual mode, the system does not perform calculations or update the output fields automatically. To recalculate, you must press the blue button immediately to the right of the Recalculate mode pulldown, press F9 on your keyboard, or switch to Automatic mode.
Tip: In Automatic mode, the system may appear to become unresponsive while recalculating. If you are making multiple changes, you may find it a better experience to select Manual mode, and recalculate only once, after you have entered all your changes.

Total Thermal Power

The Total thermal power field estimates the total thermal power consumed by all FPGA resources on the specific page. Some pages may also provide a breakdown of the components contributing to the total thermal power. The total thermal power displayed in individual pages does not include static power, which is reported in the Power Summary for the whole device.

Thermal power is the power dissipated in the device. Total Thermal Power fields on individual pages contain the sum of dynamic and standby thermal power of all the resources used in the device. Total thermal power includes only the thermal component for the I/O page and does not include external power dissipation, such as from voltage-referenced termination resistors.

Resource Utilization

Most pages contain one or more fields that provide an estimate of the percentage resource utilization for the modules in the specific page. Such values are calculated based on the maximum available resources of a given type for a selected device. If resource utilization exceeds 100%, it indicates that the current device may not be able to support the resources entered into the page.

Power Rail Current Consumption

Most pages include a table showing the dynamic current consumption for all power rails used by the FPGA resources in the specific page. The same power rail may appear in multiple pages, and the dynamic currents reported in the Report page are the sums of all corresponding currents for a given rail at a given voltage in individual pages. The Report page also includes static currents, which are not reported in individual pages.

Note: For Intel® Agilex™ devices, verify that you set the Power Characteristics field on the Main page to Maximum. The PTC does not report the current for a given power rail when you set Power Characteristics to Typical.

Why Typical Power Might Appear Larger than Maximum Power ( Intel® Stratix® 10 Devices Only)

Due to the methodologies employed by power modeling, instances can occur where the typical power for an Intel® Stratix® 10 device may appear to be higher than the maximum power. Every Intel® Stratix® 10 device is tested during the manufacturing process; this testing includes measuring the maximum static current drawn by each device rail, and total static power consumed across all rails. A given device does not draw maximum current on each rail simultaneously — consequently, the total static power actually consumed by the device in operation, is going to be lower than the sum of the individual maximum static powers measured for each rail.

The PTC Report page (and the Intel® Quartus® Prime Power Analyzer per-rail report) indicate the maximum per-rail static currents based on actual measurements, to help you choose appropriate voltage regulators. However, when calculating total thermal power and total static power, we make more realistic — and generally lower — assumptions for total static power across all rails.

Maximum power values are helpful for determining the proper regulator size for power delivery, and the proper thermal solution for cooling, to ensure operation to published specifications.

Typical power values are helpful for estimating average battery life or total cost of ownership. Typical values account for variations in process and are not based on real measurements of individual devices — they are not guaranteed values.

Instances can arise where the typical power reported may be larger than the maximum power. This aberration is a consequence of the modeling methods used, and is not indicative of an error.

Register Dynamic Power in Intel® Agilex™ Devices

In Intel® Agilex™ devices, register dynamic power includes the power consumed by all of a resister's ports, including its clock ports. Because the clock ports consume power, a register with a non-zero clock frequency will also have non-zero power consumption, even if you have set the Toggle % column value to zero.