PA-7500 running 11.1.x or higher reporting that actual power provided by the power supplies is less used power

• On PA-7500 running on PANOS 11.1.x, the CLI output for the command “show chassis power” displays Actual power provide by the power supplies is less than the actual power used.
• As displayed in the output below, sum of actual power used by all the components (slots and the fan trays) = 6630W.
• However the sum of actual power provided by the Power Supply Units(PSx) = 6516W, which is less than the power used.
• No Operational impact because of the issue.

> show chassis power

Slot       Component            Card Status        Power (w)       Actual (w)
1          PA-7500-NPC-A        Up                 1150            439
2          PA-7500-NPC-A        Up                 1150            414
3          PA-7500-DPC-A        Up                 1200            739
4          PA-7500-DPC-A        Up                 1200            719
5          PA-7500-MPC-A        Up                 800             390
6          PA-7500-DPC-A        Up                 1200            763
7          PA-7500-DPC-A        Up                 1200            716
8          PA-7500-DPC-A        Up                 1200            741
9          PA-7500-DPC-A        Up                 1200            758
10         PA-7500-SFC-A        Up                 400             306
11         PA-7500-SFC-A        Up                 400             293


FANTRAY1   PA-7500-FAN-A        Present            150             25
FANTRAY2   PA-7500-FAN-A        Present            150             23
FANTRAY3   PA-7500-FAN-A        Present            150             23
FANTRAY4   PA-7500-FAN-A        Present            150             23
FANTRAY5   PA-7500-FAN-A        Present            150             23
FANTRAY6   PA-7500-FAN-A        Present            150             23
FANTRAY7   PA-7500-FAN-A        Present            150             23
FANTRAY8   PA-7500-FAN-A        Present            150             24
FANTRAY9   PA-7500-FAN-A        Present            150             23
FANTRAY10  PA-7500-FAN-A        Present            150             23
FANTRAY11  PA-7500-FAN-A        Present            150             24
FANTRAY12  PA-7500-FAN-A        Present            150             24
FANTRAY13  PA-7500-FAN-A        Present            150             24
FANTRAY14  PA-7500-FAN-A        Present            150             24
FANTRAY15  PA-7500-FAN-A        Present            150             23


PS1        PAN-PWR-3600W-AC     OK                 3600            667 (+)
PS2        PAN-PWR-3600W-AC     OK                 3600            671 (+)
PS3        PAN-PWR-3600W-AC     OK                 3600            647 (+)
PS4        PAN-PWR-3600W-AC     OK                 3600            637 (+)
PS5        PAN-PWR-3600W-AC     OK                 3600            650 (+)
PS6        PAN-PWR-3600W-AC     OK                 3600            650 (+)
PS7        PAN-PWR-3600W-AC     OK                 3600            640 (+)
PS8        PAN-PWR-3600W-AC     OK                 3600            637 (+)
PS9        PAN-PWR-3600W-AC     OK                 3600            663 (+)
PS10       PAN-PWR-3600W-AC     OK                 3600            654 (+)


           Provided:                               36000           6516 <<
           Used:                                   13350           6630 <<<
           Remaining:                              22650

• PA-7500
• PANOS 11.1.x

• In older chassis models such as  PA-7050/7080, the "Provided" power value was a static calculation based on PSU (Power Supply Unit) labels rather than actual real-time measurements. Because the firewall assumed these theoretical maximums were always available, it would attempt to power on new line cards even if the actual power supply was insufficient, leading to potential stability issues or failures.

• With PA-7500, Provided power is no longer a static theoretical number. It is a true, measured rolling average of the actual wattage the PSUs draw over a periodic polling interval. This allows the chassis to make informed decisions about whether it is actually safe to power on a new component based on the actual power currently available.

• Since an instantaneous snapshot of the Line Cards against a smoothed average from the PSUs is being compared, a brief traffic spike may cause the used value to momentarily look higher than the Provided average in the CLI output.

• The (+) symbol next to the PSUs Actual values (e.g., PS1: 667 (+)) visually warns the administrator about this averaging behavior. 

1. Behavior is working as expected