Your routers and switches display power usage counters, but what are they representing and can you trust them? Let’s try to answer these questions today.
Introduction
Different initiatives around power are ongoing, from characterization (power calculators) to network-level power optimization, but today we will focus on the observability part: what can we monitor and can we trust these numbers.
Figure 1: HPE Juniper Networking Initiatives around Energy
TL;DR
“It's an awfully long article, I’m a busy engineer and don’t have time for all the details, just gimme the results please...”
Ok, ok… I admit it's a very long article, so the following chart displays in a synthetic manner:
- Does the product offer a counter for Input Power (check the definition of input/output power in following section) and if it does support it, what is the CLI exposing this counter?
- When the counter is available, what’s the level of accuracy you can expect?
| Product |
Output Power |
Input Power |
Accuracy Delta of CLI
Compared to PDU |
MX204
(Junos) |
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
|
MX240 Chassis
(Junos)
|
show chassis power
show chassis env pem
|
Not Available |
Not Applicable since
Input is not available |
MX480 Chassis
(Junos)
|
show chassis power
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
MX960 Chassis
(Junos)
|
show chassis power
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
MX301
(Junos)
|
show chassis power
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
MX304
(Junos)
|
show chassis power
show chassis env pem |
show chassis env pem |
Measured 2%
deviation |
MX10000 Chassis
(Junos)
|
show chassis power
show chassis env pem |
show chassis env pem |
Measured from 2 to 5%
deviation |
PTX10001-36MR
(Junos EVO) |
show chassis power |
show chassis power |
Identical |
PTX10002-36QDD
(Junos EVO)
|
show chassis power |
show chassis power |
Identical |
PTX10000 Chassis
(Junos EVO)
|
show chassis power |
show chassis power |
Identical |
ACX7020
(Junos EVO)
|
Not Available |
show chassis power
(only total) |
Not Applicable since
Input is not available |
ACX7024(X)
(Junos EVO)
|
show chassis power |
show chassis power |
Identical |
ACX7100
(Junos EVO)
|
show chassis power |
show chassis power |
Identical |
ACX7300
(Junos EVO)
|
show chassis power |
show chassis power |
Not measured |
ACX7500
(Junos EVO)
|
show chassis power |
show chassis power |
Not measured |
QFX5110
(Junos)
|
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
QFX5120
(Junos)
|
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
QFX5130
(Junos EVO)
|
show chassis power |
show chassis power |
Identical |
QFX5200
(Junos)
|
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
QFX5210
(Junos)
|
show chassis env pem |
Not Available |
Not Applicable since
Input is not available |
QFX5220
(Junos EVO)
|
show chassis power |
show chassis power |
Not measured |
QFX5230
(Junos EVO)
|
show chassis power |
show chassis power |
Not measured |
QFX5240/5241
(Junos EVO)
|
show chassis power |
show chassis power |
Identical |
QFX5700(E)
(Junos EVO)
|
show chassis power |
show chassis power |
Not measured |
Long story short, when the counters are available, it’s pretty accurate and reliable. We didn't have all the combinations of devices and PDU to measure it exhaustively, but when the metrology was available, we verified we can fully trust it.
Principles and Vocabulary
The devices are hosted in a rack and receive the power from a Power Distribution Unit present in this rack.
Figure 2: Abstracted View of a chassis and the different currents
It’s common for networking device to expose the “Output power”, basically the amount of energy exiting the Power Supply Module and feeding the different power buses of the system. This number doesn’t represent the power actually consumed by the device or provided by the PDU, but only how much is left after the voltage conversion performed by the different Power Modules (referred as PSMs or PEMs depending on the platform).
Except for the PTX12000 and legacy MX240/480/960 chassis, most of the routers and switches in the HPE Juniper Networking portfolio are operating with 12V DC out of the power module. This current is converted in different places of the devices (we talk about Point of Load or PoL) to lower voltage: 5V, 3V, 0.8V, etc depending on the components’ requirements.
The Output 12V DC current consumption is different from what is injected into the power modules. That’s where the concepts of conversion efficiency and ratings are coming from. You know, the “80 Plus” ratings (Bronze, Silver, Gold, Platinum, Titanium, etc.): it represents the amount of energy lost during the conversion from the Grid to the 12V DC needed by the device.
Some products will expose an “Input Power” counter. It represents the voltage, amperage and power received by the Power Module from the grid.
Now the question we will try to answer today is: “how accurate are these counters and how far can we trust them?”
The good news is we can precisely monitor the wall-side current in our POC labs. Indeed, the Power Distribution Units (PDUs) can measure the energy they inject into the networking devices, at the outlet level. We will refer to the PDUs’ GUI to collect this information and compare it with the counters on the routers.
Figure 3: Power Measurement Points
The Figure 3 above represents the counters we will collect and compare.
Note: the division of your output and input wattage gives you your conversion ratio/efficiency.
The main objectives of this article are the following:
- Identify the products exposing input power counters
- Clarify the CLI used to expose these counters
- When possible, compare the Input Current in the router CLI to the Outlet output current from the PDU and verify the accuracy
Disclaimers and Methodology
It’s important to understand the following points before proceeding:
- Many factors are influencing the power utilization, starting from temperature, elevation and device utilization. We described these parameters at length in this article PTX10000 Power Optimization https://community.juniper.net/blogs/nicolas-fevrier/2023/08/29/ptx10000-power-optimization and video: What does Influence Power Consumption on Networking Devices? https://www.youtube.com/watch?v=-aEYNDRB9Ck
- The lab is not a controlled environment and doesn’t try to answer the question “how much is consumed by product X, Y or Z?” but instead, we want to know “what’s available and how accurate are the power usage counters exposed on product X, Y or Z?”.
- By nature, power usage is fluctuating. The collection of power consumption counter is just a snapshot of the situation at a given time. That’s why we recommend using:
- Telemetry and data visualization (Grafana-like dashboards) to draw an average view
- If CLI is your only option, collect a dozen of times and calculate an average value. It’s not perfect, but still better than just one snapshot number.
- And when you’ll look at the fluctuating measurements, you’ll understand that a margin of error of a couple of watts is the norm, sometimes it varies in a range of 10 Watts. So don’t waste time collecting values with decimals.
That's the approach we took for this study, we collected 10 to 12 show commands in less than a minute and we calculated the average value. For the sake of brevity, we will only display one show command in the outputs below, but consider we will calculate the deviation based on an averaged data collection.
Devices with No Counters For “Input Power”
Let’s start listing the boxes that don’t expose the input power. Of course, no point trying to verify the accuracy of the measurement.
MX204
jnpr@mx204-205> show chassis po
^
syntax error.
jnpr@mx204-205> show chassis ?
Possible completions:
alarms Show alarm status
ambient-temperature Show chassis ambient temperature
environment Show component status and temperature, cooling system speeds
errors Show chassis errors
fan Show fan and fan tray information
firmware Show firmware and operating system version for components
fpc Show Flexible PIC Concentrator status
fru Show fru replacement status
hardware Show installed hardware components
hss Show SerDes information
location Show physical location of chassis
mac-addresses Show media access control addresses
memory-usage-chassisd Dump LMLD data to /var/log/chassisd_memory_usage
network-services Show chassis network services
pic Show Physical Interface Card state, type, and uptime
routing-engine Show Routing Engine status
satellite-cluster Show Satellite Cluster information
synchronization Show clock synchronization information
temperature-thresholds Show chassis temperature threshold settings
jnpr@mx204-205>
jnpr@mx204-205> show chassis environment pem
PEM 0 status:
State Online
Airflow Front to Back
Temp Sensor 0 37 degrees C / 98 degrees F
Temp Sensor 1 35 degrees C / 95 degrees F
Firmware version 00.05
Fan Sensor 5970 RPM
DC Output Voltage(V) Current(A) Power(W) Load(%)
11.90 15.00 178 27
Health check Information:
Status: Unsupported
PEM 1 status:
State Offline
Health check Information:
Status: Unsupported
jnpr@mx204-205>
Only the Output power can be monitored and through the "show chassis env" output.
Input power is not monitored.
MX240 Chassis
jnpr@mx240-207-re0> show chassis power detail
PEM 0:
State: Online
AC input: OK (1 feed expected, 1 feed connected)
Capacity: 2400 W (maximum 2400 W)
DC output: 114 W (zone 0, 2 A at 57 V, 4% of capacity)
PEM 1:
State: Present
AC input: Out of range (1 feed expected, 1 feed connected)
Capacity: 2400 W (maximum 2400 W)
DC output: 0 W (zone 0, 0 A at 0 V, 0% of capacity)
PEM 2:
State: Empty
Input: Absent
PEM 3:
State: Empty
Input: Absent
System:
Zone 0:
Capacity: 2400 W (maximum 2400 W)
Allocated power: 250 W (2150 W remaining)
Actual usage: 114 W
Total system capacity: 2400 W (maximum 2400 W)
Total remaining power: 2150 W
jnpr@mx240-207-re0> show chassis environment pem
PEM 0 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
57 2 114 4
PEM 1 status:
State Present
jnpr@mx240-207-re0>
Only the Output power can be monitored and is available in both "show chassis power" and "show chassis env" outputs.
MX480 Chassis
jnpr@ASHBVALB-MSE01-AA-IE1> show chassis power detail
PEM 0:
State: Online
AC input: OK (1 feed expected, 1 feed connected)
Capacity: 2050 W (maximum 2050 W)
DC output: 580 W (zone 0, 10 A at 58 V, 28% of capacity)
PEM 1:
State: Online
AC input: OK (1 feed expected, 1 feed connected)
Capacity: 2050 W (maximum 2050 W)
DC output: 627 W (zone 0, 11 A at 57 V, 30% of capacity)
PEM 2:
State: Present
AC input: Out of range (1 feed expected, 1 feed connected)
Capacity: 2050 W (maximum 2050 W)
DC output: 0 W (zone 0, 0 A at 0 V, 0% of capacity)
PEM 3:
State: Present
AC input: Out of range (1 feed expected, 1 feed connected)
Capacity: 2050 W (maximum 2050 W)
DC output: 0 W (zone 0, 0 A at 0 V, 0% of capacity)
System:
Zone 0:
Capacity: 4100 W (maximum 4100 W)
Allocated power: 2236 W (1864 W remaining)
Actual usage: 1207 W
Total system capacity: 4100 W (maximum 4100 W)
Total remaining power: 1864 W
Item Used(W) Max(W)
CB 0 + RE 0 242 390
CB 0 197 280
CB 1 + RE 1 300 510
CB 1 252 400
FPC 2 283 376
FPC 3 275 465
FPC 5 300 465
{master}
jnpr@ASHBVALB-MSE01-AA-IE1> show chassis environment pem
PEM 0 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
58 10 580 28
PEM 1 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
57 11 627 30
PEM 2 status:
State Present
PEM 3 status:
State Present
{master}
jnpr@ASHBVALB-MSE01-AA-IE1>
Only the Output power can be monitored and is available in both "show chassis power" and "show chassis env" outputs.
MX960 Chassis
jnpr@NYCMNY-VFTTP-395_RE0> show chassis power detail
PEM 0:
State: Online
AC input: OK (2 feed expected, 2 feed connected)
Capacity: 4100 W (maximum 4100 W)
DC output: 1026 W (zone 0, 18 A at 57 V, 25% of capacity)
PEM 1:
State: Online
AC input: OK (2 feed expected, 2 feed connected)
Capacity: 4100 W (maximum 4100 W)
DC output: 1824 W (zone 1, 32 A at 57 V, 44% of capacity)
PEM 2:
State: Online
AC input: OK (2 feed expected, 2 feed connected)
Capacity: 4100 W (maximum 4100 W)
DC output: 855 W (zone 0, 15 A at 57 V, 20% of capacity)
PEM 3:
State: Empty
Input: Absent
System:
Zone 0:
Capacity: 4100 W (maximum 4100 W)
Allocated power: 3090 W (1010 W remaining)
Actual usage: 1881 W
Zone 1:
Capacity: 4100 W (maximum 4100 W)
Allocated power: 3155 W (945 W remaining)
Actual usage: 1824 W
Total system capacity: 8200 W (maximum 8200 W)
Total remaining power: 1955 W
Item Used(W) Max(W)
CB 0 + RE 0 351 510
CB 0 306 400
CB 1 + RE 1 346 510
CB 1 302 400
CB 2 293 400
FPC 1 249 465
FPC 2 252 465
FPC 3 253 465
FPC 4 265 465
FPC 5 265 465
FPC 8 249 465
FPC 9 260 465
FPC 10 260 465
FPC 11 259 465
{master}
jnpr@NYCMNY-VFTTP-395_RE0> show chassis environment pem
PEM 0 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
57 19 1083 26
PEM 1 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
57 32 1824 44
PEM 2 status:
State Online
Temperature OK
DC Output Voltage(V) Current(A) Power(W) Load(%)
57 15 855 20
{master}
jnpr@NYCMNY-VFTTP-395_RE0>
Only the Output power can be monitored and is available in both "show chassis power" and "show chassis env" outputs.
MX301
jnpr@mx301-202> show chassis power detail
PEM 0:
State: Online
Capacity: 850 W (maximum 850 W)
AC input: OK (INP1 feed expected, INP1 feed connected)
DC output: 145 W (zone 0, 12.00 A at 12.13 V, 17% of capacity)
PEM 1:
State: Offline
Capacity: 850 W (maximum 850 W)
AC input: Not ready
DC output: 0 W (zone 0, 0.00 A at 0.00 V, 0% of capacity)
System:
Zone 0:
Capacity: 850 W (maximum 850 W)
Allocated power: 820 W (30 W remaining)
Actual usage: 145 W
Total system capacity: 850 W (maximum 850 W)
Total remaining power: 30 W
Item Used(W)
Fan Tray 0 1
Fan Tray 1 1
Fan Tray 2 1
Fan Tray 3 1
Fan Tray 4 1
Fan Tray 5 1
RE0/CB0 51
FPC 0 99
jnpr@mx301-202> show chassis environment pem
PEM 0 status:
State Online
Airflow Front to Back
Primary Hot Spot 42 degrees C / 107 degrees F
Temp Sensor 1 31 degrees C / 87 degrees F
Air Outlet ambient 40 degrees C / 104 degrees F
Secondary Hot Spot 44 degrees C / 111 degrees F
Fan 0 4875 RPM
Fan 1 4650 RPM
DC Output Voltage(V) Current(A) Power(W) Load(%)
12.13 11.50 139 16
Health check Information:
Status: Unsupported
PEM 1 status:
State Offline
Health check Information:
Status: Unsupported
jnpr@mx301-202>
Only the Output power can be monitored and is available in both "show chassis power" and "show chassis env" outputs.
ACX7020
regress@rtme-acx7020-01> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 47
PSM 0
State: Online
Capacity 220 W (maximum 220 W)
PSM 1
State: Online
Capacity 220 W (maximum 220 W)
System:
Zone 0:
Capacity: 440 W (maximum 440 W)
Actual usage: 48 W
Total system capacity: 440 W (maximum 440 W)
regress@rtme-acx7020-01> show chassis environment psm
PSM 0 status:
State Online
DC Output OK
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
PSM 1 status:
State Online
DC Output OK
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
regress@rtme-acx7020-01>
The ACX7020 output is pretty unique compared to other Junos or EVO platforms since it displays only the Total input power in the "show chassis power" CLI. But in reality, this number represents the power coming into the hotswap controller after the power supply unit. This number corresponds to the "Output Power" we express on other platforms.
QFX5110/QFX5120/QFX5200/QFX5210
root@5a7-qfx4> show chassis environment pem
localre:
--------------------------------------------------------------------------
FPC 0 PEM 0 status:
State Present
FPC 0 PEM 1 status:
State Online
Airflow Back to Front
Temp Sensor 0 OK 51 degrees C / 123 degrees F
Temp Sensor 1 OK 30 degrees C / 86 degrees F
Temp Sensor 2 OK 24 degrees C / 75 degrees F
Fan 0 4140 RPM
Fan 1 3960 RPM
DC Output Voltage(V) Current(A) Power(W) Load(%)
12 10 120 18
{master:0}
root@5a7-qfx4>
Only the Output power can be monitored and through the "show chassis env" output. Input power is not monitored.
All these QFX switches running Junos (non-EVO) have the same CLI output.
Devices with “Input Power” Counters
MX304
More or less 594W measured on the PDU
jnpr@mx304-219-re0> show chassis power detail
PEM 0:
State: Online
Capacity: 2200 W (maximum 2200 W)
AC input: OK (INPIN feed expected, INPINP1 feed connected)
DC output: 556 W (zone 0, 46.19 A at 12.05 V, 25% of capacity)
PEM 1:
State: Offline
Capacity: 2200 W (maximum 2200 W)
AC input: Not ready
DC output: 0 W (zone 0, 0.00 A at 0.00 V, 0% of capacity)
System:
Zone 0:
Capacity: 2200 W (maximum 2200 W)
Allocated power: 1845 W (355 W remaining)
Actual usage: 556 W
Total system capacity: 2200 W (maximum 2200 W)
Total remaining power: 355 W
Item Used(W)
Fan Tray 0 4
Fan Tray 1 4
Fan Tray 2 3
SFB 0 98
FPC 0 345
RE0 46
RE1 52
{master}
jnpr@mx304-219-re0> show chassis environment pem
PEM 0 status:
State Online
Airflow Front to Back
Inlet Ambient Temp 34 degrees C / 93 degrees F
Secondary SR Hotspot 43 degrees C / 109 degrees F
Temp Sensor 2 43 degrees C / 109 degrees F
Firmware version 1.5, 2.5
Fan 0 12992 RPM
DC Output Voltage(V) Current(A) Power(W) Load(%)
12.05 45.62 549 24
Input Voltage(V) Current(A) Power(W)
INP INP1 233.5 2.5 570.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-19 10:41:35
PEM 1 status:
State Offline
Input Voltage(V) Current(A) Power(W)
INP INP1 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-19 10:41:35
jnpr@mx304-219-re0>
Input power is available in the "show chassis env pem", grep on "INP INP1" to shorten it.
We collected 581.3W in average on the CLI vs 584W approximately on the PDU. That's 2.2% less on the CLI compared to the rack info.
MX10008 Chassis
PEM0:
from 1014W to 1018W measured on the PDU, let’s take a midpoint at 1016W
PEM2:
from 1055W to 1061W measured on the PDU, let’s take a midpoint at 1058W
On the CLI:
jnpr@mx10008-200-re0> show chassis power detail
PEM 0:
State: Online
Capacity: 5000 W (maximum 5500 W)
AC input: OK (INP1 feed expected, INP1 feed connected)
Feed1: AC input
DC output: 927 W (zone 0, 75.66 A at 12.26 V, 16% of capacity) (30A input select)
PEM 1:
State: Present
Capacity: 0 W (maximum 5500 W)
AC input: Not ready
Feed1: AC input
DC output: 0 W (zone 0, 0.00 A at 0.00 V, 0% of capacity)
PEM 2:
State: Online
Capacity: 2800 W (maximum 5500 W)
AC input: OK (INP1 feed expected, INP1 feed connected)
Feed1: AC input
DC output: 962 W (zone 0, 78.74 A at 12.22 V, 17% of capacity) (20A input select)
PEM 3:
State: Present
Capacity: 0 W (maximum 5500 W)
AC input: Not ready
Feed1: AC input
DC output: 0 W (zone 0, 0.00 A at 0.00 V, 0% of capacity)
PEM 4:
State: Present
Capacity: 0 W (maximum 5500 W)
AC input: Not ready
Feed1: AC input
DC output: 0 W (zone 0, 0.00 A at 0.00 V, 0% of capacity)
PEM 5:
State: Present
Capacity: 0 W (maximum 5500 W)
AC input: Not ready
Feed1: AC input
DC output: 0 W (zone 0, 0.00 A at 0.00 V, 0% of capacity)
System:
Zone 0:
Capacity: 7800 W (maximum 7800 W)
Allocated power: 7334 W (466 W remaining)
Actual usage: 1889 W
Total system capacity: 7800 W (maximum 7800 W)
Total remaining power: 466 W
Item Used(W)
Fan Tray 0 236
Fan Tray 1 225
RE0/CB0 90
RE1/CB1 92
Item Used(W) Max(W)
SFB 0 123 400
SFB 1 120 400
SFB 2 125 400
SFB 3 129 400
SFB 4 123 400
SFB 5 125 400
FPC 0 517 1770
jnpr@mx10008-200-re0> show chassis environment pem
PEM 0 status:
State Online
Airflow Front to Back
Temp Sensor 0 32 degrees C / 89 degrees F
Firmware version AA17AA17.AB15AB15.AC27
Fan 0 3968 RPM
Fan 1 4640 RPM
DC Output Voltage(V) Current(A) Power(W) Load(%)
12.26 75.66 927 16
Input Voltage(V) Current(A) Power(W)
INP 1 228.0 4.6 1053.4
INP 2 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-27 08:40:23
PEM 1 status:
State Present
Input Voltage(V) Current(A) Power(W)
INP 1 0.0 0.0 0.0
INP 2 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-27 08:40:23
PEM 2 status:
State Online
Airflow Front to Back
Temp Sensor 0 36 degrees C / 96 degrees F
Firmware version AA17AA17.AB15AB15.AC27
Fan 0 4384 RPM
Fan 1 5056 RPM
DC Output Voltage(V) Current(A) Power(W) Load(%)
12.22 78.74 962 17
Input Voltage(V) Current(A) Power(W)
INP 1 229.9 4.8 1094.3
INP 2 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-27 08:40:23
PEM 3 status:
State Present
Input Voltage(V) Current(A) Power(W)
INP 1 0.0 0.0 0.0
INP 2 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-27 08:40:23
PEM 4 status:
State Present
Input Voltage(V) Current(A) Power(W)
INP 1 0.0 0.0 0.0
INP 2 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-27 08:40:23
PEM 5 status:
State Present
Input Voltage(V) Current(A) Power(W)
INP 1 0.0 0.0 0.0
INP 2 0.0 0.0 0.0
Health check Information:
Status: Scheduled
Last Result: Not Performed Yet
Last Execution: Empty
Next Scheduled Run: 2026-05-27 08:40:23
jnpr@mx10008-200-re0>
Input power is available in the "show chassis env pem", grep on "INP INP1" to shorten it.
PEM0: We collected 1069W in average on the CLI vs 1016W approximately on the PDU.
That's around 5% more on the CLI compared to the rack info.
PEM2: We collected 1088W in average on the CLI vs 1058W approximately on the PDU.
That's around 3% more on the CLI compared to the rack info.
PTX10001-36MR
Approximately 758W measured on the PDU
On the CLI:
jnpr@ptx10001-216> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 760
PSM 0
State: Online
Input 1 236 760
Output 11.99 700.15
Capacity 3000 W (maximum 3000 W)
PSM 1
State: Offline
Input 1 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
Item Used(W)
Routing Engine 0 34
CB 0 5
System:
Zone 0:
Capacity: 3000 W (maximum 3000 W)
Actual usage: 760 W
Total system capacity: 3000 W (maximum 3000 W)
jnpr@ptx10001-216> show chassis environment psm
PSM 0 status:
State Online
Temperature 33 degrees C / 91 degrees F
Fans OK
DC Output OK
Hours Used 26610
Firmware Version 0212.0214
Fan 1 14976
Fan 2 13248
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-25 10:52:30 CEST
PSM 1 status:
State Offline
Temperature 31 degrees C / 87 degrees F
Fans OK
DC Output Failed
Hours Used 300
Firmware Version 0212.0214
Fan 1 0
Fan 2 0
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-25 10:52:40 CEST
jnpr@ptx10001-216>
Both input and output details are provided in the "show chassis power" CLI.
- grep on "Output" for output power
- grep on "Input 1" for input power
We collected 759.8W in average on the CLI vs 758W approx. on the PDU. It's a marginal difference.
PTX10002-36QDD
Around 420W measured on the PDU
On the CLI:
jnpr@ptx10002-204> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 416
PSM 0
State: Online
Input 1 233 416
Output 12.01 367.91
Capacity 3000 W (maximum 3000 W)
PSM 1
State: Offline
Input 1 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
Item Used(W)
Routing Engine 0 67
FPC 0 278
Fan Tray 0 1
Fan Tray 1 4
Fan Tray 2 1
System:
Power mode: Normal
Zone 0:
Capacity: 3000 W (maximum 3000 W)
Allocated power: 2858 W (142 W remaining)
Actual usage: 367 W
Total system capacity: 3000 W (maximum 3000 W)
Total remaining power: 142 W
jnpr@ptx10002-204> show chassis environment psm
PSM 0 status:
State Online
Temperature 29 degrees C / 84 degrees F
Fans OK
DC Output OK
Hours Used 14391
Firmware Version 0212.0215
Fan 1 11968
Fan 2 10560
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-22 13:32:49 CEST
PSM 1 status:
State Offline
Temperature 30 degrees C / 86 degrees F
Fans OK
DC Output Failed
Hours Used 51
Firmware Version 0212.0215
Fan 1 0
Fan 2 0
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-22 13:32:59 CEST
jnpr@ptx10002-204>
Both input and output details are provided in the "show chassis power" CLI.
- grep on "Output" for output power
- grep on "Input 1" for input power
We collected 417.2W in average on the CLI vs roughly 420W on the PDU. It's a marginal difference.
PTX10000 Chassis
The router in our lab is using 3x PEMs:
PEM0
On the PDU, it's oscillating between 681 and 702W, let's take a mid-point of 692W for this exercise.
PEM1
Oscillating between 687 and 719W, let's take a mid-point of 703W for this exercise.
PEM2
Oscillating between 672 and 684W, let's take a mid-point of 678W for this exercise.
On the CLI:
jnpr@ptx10004-204-re0-re0> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 2112
PSM 0
State: Online
INP1 229 696
INP2 0 0
Output 12.23 608.32 (30A input select)
Capacity 5000 W (maximum 5500 W)
PSM 1
State: Online
INP1 231 720
INP2 0 0
Output 12.21 628.84 (30A input select)
Capacity 5000 W (maximum 5500 W)
PSM 2
State: Online
INP1 233 696
INP2 0 0
Output 12.21 596.6 (30A input select)
Capacity 5000 W (maximum 5500 W)
Item Used(W)
CB 0 75
FPC 0 817
SIB 0 125
SIB 1 126
SIB 2 125
SIB 3 127
SIB 4 125
SIB 5 125
Fan Tray 0 76
Fan Tray 1 83
System:
Zone 0:
Capacity: 15000 W (maximum 16500 W)
Allocated power: 6210 W (8790 W remaining)
Actual usage: 1833 W
Total system capacity: 15000 W (maximum 16500 W)
Total remaining power: 8790 W
{master}
jnpr@ptx10004-204-re0-re0> show chassis environment psm
PSM 0 status:
State Online
Temperature 27 degrees C / 80 degrees F
Fans OK
AC Input1 OK
AC Input2 Check
Check Input1 Alarm No
Check Input2 Alarm Yes
DC Output OK
Hours Used 33293
Firmware Version aa17.aa17.ab15.ab15.ac27
Fan 1 5120
Fan 2 6016
HVDC Mode Both Inputs AC
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-02-18 12:07:00 CET
PSM 1 status:
State Online
Temperature 33 degrees C / 91 degrees F
Fans OK
AC Input1 OK
AC Input2 Check
Check Input1 Alarm No
Check Input2 Alarm Yes
DC Output OK
Hours Used 36987
Firmware Version aa17.aa17.ab15.ab15.ac27
Fan 1 5152
Fan 2 6016
HVDC Mode Both Inputs AC
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-02-18 12:07:00 CET
PSM 2 status:
State Online
Temperature 29 degrees C / 84 degrees F
Fans OK
AC Input1 OK
AC Input2 Check
Check Input1 Alarm No
Check Input2 Alarm Yes
DC Output OK
Hours Used 46798
Firmware Version aa17.aa17.ab15.ab15.ac27
Fan 1 5120
Fan 2 6016
HVDC Mode Both Inputs AC
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-02-18 12:07:00 CET
{master}
jnpr@ptx10004-204-re0-re0>
Both input and output information present in the "show chassis power" CLI.
On PEM0, we took a mid-point of 692W for this exercise, compared to 696W, that's 99%
On PEM1, we took a mid-point of 703W for this exercise, compared to 720W, that's 98%
On PEM2, we took a mid-point of 678W for this exercise, compared to 696W, that's 97%.
Considering the constant variation, these calculations don't make much sense, we can just say the results are pretty much aligned.
ACX7024
Around 87W measured on the PDU
On the CLI:
jnpr@acx7024-208> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 88
PSM 0
State: Online
Input 234 88
Output 12.15 75.31
Capacity 400 W (maximum 400 W)
PSM 1
State: Offline
Input 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
System:
Zone 0:
Capacity: 400 W (maximum 400 W)
Actual usage: 88 W
Total system capacity: 400 W (maximum 400 W)
jnpr@acx7024-208> show chassis environment pem
PSM 0 status:
State Online
Temperature 23 degrees C / 73 degrees F
Fans OK
DC Output OK
Firmware Version 15.17
Fan 1 6000
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-27 17:14:51 CEST
PSM 1 status:
State Offline
Temperature 23 degrees C / 73 degrees F
Fans OK
DC Output Failed
Firmware Version 15.17
Fan 1 0
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-27 17:15:01 CEST
jnpr@acx7024-208>
Both input and output information present in the "show chassis power" CLI. The difference between the average data collected from CLI (88W) and the current measured on the PDU (87W) is marginal.
ACX7100
Around 446W measured on the PDU
On the CLI:
jnpr@acx7100-202> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 443
PSM 0
State: Online
Input 231 443
Output 11.98 409.1
Capacity 1600 W (maximum 1600 W)
PSM 1
State: Offline
Input 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
System:
Zone 0:
Capacity: 1600 W (maximum 1600 W)
Actual usage: 409 W
Total system capacity: 1600 W (maximum 1600 W)
jnpr@acx7100-202> show chassis environment pem
PSM 0 status:
State Online
Temperature 30 degrees C / 86 degrees F
Fans OK
DC Output OK
Firmware Version 21.43
Fan 1 17984
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-27 00:23:41 CEST
PSM 1 status:
State Offline
Temperature 35 degrees C / 95 degrees F
Fans OK
DC Output Failed
Firmware Version 00.00
Fan 1 0
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-27 00:23:51 CEST
jnpr@acx7100-202>
Both input and output information present in the "show chassis power" CLI. The difference between the average data collected from CLI (443.5W) and the current measured on the PDU (446W) is marginal.
ACX73xx
We didn't have it behind controlled PDU, we were not able to perform comparison tests.
On the CLI:
regress@rtme-acx7332-01-re0> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 422
PSM 0
State: Online
Input 200 211
Output 12.17 167.36
Capacity 2200 W (maximum 2200 W)
PSM 1
State: Online
Input 202 211
Output 12.2 154.44
Capacity 2200 W (maximum 2200 W)
Item Used(W)
Routing Engine 0 44
CB 0 18
FPC 2 35
FPC 3 23
Fan Tray 0 6
Fan Tray 1 5
Fan Tray 2 5
Fan Tray 3 4
FEB 0 197
System:
Zone 0:
Capacity: 4400 W (maximum 4400 W)
Allocated power: 1690 W (2710 W remaining)
Actual usage: 349 W
Total system capacity: 4400 W (maximum 4400 W)
Total remaining power: 2710 W
{master}
regress@rtme-acx7332-01-re0> show chassis environment psm
PSM 0 status:
State Online
Temperature 25 degrees C / 77 degrees F
Fans OK
DC Output OK
Hours Used 13803
Firmware Version 11.13
Fan 1 10144
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-28 11:24:33 PDT
PSM 1 status:
State Online
Temperature 25 degrees C / 77 degrees F
Fans OK
DC Output OK
Hours Used 15419
Firmware Version 11.13
Fan 1 9872
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-28 11:24:43 PDT
{master}
regress@rtme-acx7332-01-re0>
Both input and output current are exposed in the "show chassis power" CLI, but we were not able to test the accuracy of these sensors.
ACX7500
We didn't have this router behind controlled PDU, we were not able to perform comparison tests.
On the CLI:
regress@rtme-acx7509-01-re0> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 622
PSM 0
State: Online
Input 1 202 286
Output 12.01 226.83
Capacity 3000 W (maximum 3000 W)
PSM 1
State: Online
Input 1 201 336
Output 12.02 302.13
Capacity 3000 W (maximum 3000 W)
PSM 2
State: Offline
Input 1 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
PSM 3
State: Offline
Input 1 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
Item Used(W)
CB 0 66
FPC 1 102
FPC 2 55
FPC 5 77
Fan Tray 0 17
Fan Tray 1 19
FEB 0 192
FEB 1 0
System:
Zone 0:
Capacity: 6000 W (maximum 6000 W)
Allocated power: 1730 W (4270 W remaining)
Actual usage: 528 W
Total system capacity: 6000 W (maximum 6000 W)
Total remaining power: 4270 W
{master}
regress@rtme-acx7509-01-re0> show chassis environment psm
PSM 0 status:
State Online
Temperature 27 degrees C / 80 degrees F
Fans OK
DC Output OK
Hours Used 39214
Firmware Version 0210.0211
Fan 1 10048
Fan 2 8896
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-06-02 04:21:15 PDT
PSM 1 status:
State Online
Temperature 29 degrees C / 84 degrees F
Fans OK
DC Output OK
Hours Used 35646
Firmware Version 0210.0211
Fan 1 9984
Fan 2 8832
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-06-02 04:21:25 PDT
PSM 2 status:
State Offline
Temperature 30 degrees C / 86 degrees F
Fans OK
DC Output Failed
Hours Used 541
Firmware Version 0212.0214
Fan 1 0
Fan 2 0
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-06-02 04:21:35 PDT
PSM 3 status:
State Offline
Temperature 29 degrees C / 84 degrees F
Fans OK
DC Output Failed
Hours Used 545
Firmware Version 0212.0214
Fan 1 0
Fan 2 0
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-06-02 04:21:45 PDT
{master}
regress@rtme-acx7509-01-re0>
Both input and output current are exposed in the "show chassis power" CLI, but we were not able to test the accuracy of these sensors.
QFX5130
Around 257W measured on the PDU
On the CLI:
jnpr@qfx5130-208> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 256
PSM 0
State: Online
Input 1 233 256
Output 11.95 229.79
Capacity 1600 W (maximum 1600 W)
PSM 1
State: Offline
Input 1 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
System:
Zone 0:
Capacity: 1600 W (maximum 1600 W)
Allocated power: 1241 W (359 W remaining)
Actual usage: 229 W
Total system capacity: 1600 W (maximum 1600 W)
Total remaining power: 359 W
jnpr@qfx5130-208> show chassis environment pem
PSM 0 status:
State Online
Temperature 28 degrees C / 82 degrees F
Fans OK
DC Output OK
Firmware Version 21.41
Fan 1 17952
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
PSM 1 status:
State Offline
Temperature 36 degrees C / 96 degrees F
Fans OK
DC Output Failed
Firmware Version 00.41
Fan 1 0
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
jnpr@qfx5130-208>
Both input and output current information is available from "show chassis power" CLI.
In average, the CLI collection gives us 256.6W, compared to the 257W we see on the PDU, the difference is marginal.
QFX5220
On the CLI:
root@spine1> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 420
PSM 0
State: Online
Input 1 202 96
Output 12.01 75.4
Capacity 1600 W (maximum 1600 W)
PSM 1
State: Online
Input 1 202 97
Output 12.05 79.1
Capacity 1600 W (maximum 1600 W)
PSM 2
State: Online
Input 1 202 128
Output 12.04 109.12
Capacity 1600 W (maximum 1600 W)
PSM 3
State: Online
Input 1 202 99
Output 11.99 79.58
Capacity 1600 W (maximum 1600 W)
Item Used(W)
Routing Engine 0 47
FPC 0 156
System:
Zone 0:
Capacity: 6400 W (maximum 6400 W)
Allocated power: 1640 W (4760 W remaining)
Actual usage: 343 W
Total system capacity: 6400 W (maximum 6400 W)
Total remaining power: 4760 W
root@spine1> show chassis environment pem
PSM 0 status:
State Online
Temperature 28 degrees C / 82 degrees F
Fans OK
DC Output OK
Firmware Version 00.00
Fan 1 5520
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
PSM 1 status:
State Online
Temperature 31 degrees C / 87 degrees F
Fans OK
DC Output OK
Firmware Version 00.00
Fan 1 5520
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
PSM 2 status:
State Online
Temperature 29 degrees C / 84 degrees F
Fans OK
DC Output OK
Firmware Version 00.00
Fan 1 5456
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
PSM 3 status:
State Online
Temperature 34 degrees C / 93 degrees F
Fans OK
DC Output OK
Firmware Version 00.00
Fan 1 5520
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
root@spine1>
Both input and output current information is available from "show chassis power" CLI.
We don't have the proper metrology in our lab PDU to verify the accuracy of the Input counter.
QFX5230
On the CLI:
root@dc-tme-qfx5230-64cd-01> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 304
PSM 0
State: Online
Input 1 204 116
Output 11.97 97.32
Capacity 3000 W (maximum 3000 W)
PSM 1
State: Online
Input 1 203 188
Output 12 169.52
Capacity 3000 W (maximum 3000 W)
Item Used(W)
Routing Engine 0 17
FPC 0 104
System:
Zone 0:
Capacity: 6000 W (maximum 6000 W)
Allocated power: 1241 W (4759 W remaining)
Actual usage: 266 W
Total system capacity: 6000 W (maximum 6000 W)
Total remaining power: 4759 W
root@dc-tme-qfx5230-64cd-01> show chassis environment psm
PSM 0 status:
State Online
Temperature 24 degrees C / 75 degrees F
Fans OK
DC Output OK
Hours Used 20502
Firmware Version 0212.0216
Fan 1 13568
Fan 2 12032
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-06-02 18:25:30 PDT
PSM 1 status:
State Online
Temperature 25 degrees C / 77 degrees F
Fans OK
DC Output OK
Hours Used 24800
Firmware Version 0212.0216
Fan 1 13504
Fan 2 12032
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-06-02 18:25:40 PDT
root@dc-tme-qfx5230-64cd-01>
Both input and output current information is available from "show chassis power" CLI.
We don't have the proper metrology in our lab PDU to verify the accuracy of the Input counter.
QFX5240/5241
Around 502W measured on the PDU
On the CLI:
jnpr@qfx5240-217> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 500
PSM 0
State: Online
Input 1 232 500
Output 12.21 437.37
Capacity 3000 W (maximum 3000 W)
PSM 1
State: Offline
Input 1 0 0
Output 0 0
Capacity 0 W (maximum 0 W)
System:
Zone 0:
Capacity: 3000 W (maximum 3000 W)
Allocated power: 2582 W (418 W remaining)
Actual usage: 500 W
Total system capacity: 3000 W (maximum 3000 W)
Total remaining power: 418 W
jnpr@qfx5240-217> show chassis environment psm
PSM 0 status:
State Online
Temperature 33 degrees C / 91 degrees F
Fans OK
DC Output OK
Firmware Version 00.02.02
Fan 1 7328
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
PSM 1 status:
State Offline
Temperature 35 degrees C / 95 degrees F
Fans OK
DC Output Failed
Firmware Version 00.02.02
Fan 1 0
Health check Information:
Status: Health Check Not Supported
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: Not Scheduled
jnpr@qfx5240-217>
Both input and output current information is available from "show chassis power" CLI.
The average power measured on a dozen of collections from the CLI gives us 500.1W, compared to the 502W we have on the PDU, it's a marginal difference. The counter can be fully trusted.
QFX5700
On the CLI:
root@dc-tme-qfx5700-01-re0> show chassis power detail
Chassis Power Voltage(V) Power(W)
Total Input Power 478
PSM 0
State: Online
Input 1 204 220
Output 12.01 181.7
Capacity 3000 W (maximum 3000 W)
PSM 1
State: Online
Input 1 205 258
Output 12.02 219.39
Capacity 3000 W (maximum 3000 W)
Item Used(W)
CB 0 52
FPC 0 39
FPC 1 86
FPC 4 68
Fan Tray 0 11
Fan Tray 1 19
FEB 0 128
System:
Zone 0:
Capacity: 6000 W (maximum 6000 W)
Allocated power: 1690 W (4310 W remaining)
Actual usage: 478 W
Total system capacity: 6000 W (maximum 6000 W)
Total remaining power: 4310 W
{master}
root@dc-tme-qfx5700-01-re0> show chassis environment psm
PSM 0 status:
State Online
Temperature 27 degrees C / 80 degrees F
Fans OK
DC Output OK
Hours Used 21485
Firmware Version 0211.0213
Fan 1 9984
Fan 2 8896
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-30 17:58:56 UTC
PSM 1 status:
State Online
Temperature 28 degrees C / 82 degrees F
Fans OK
DC Output OK
Hours Used 21576
Firmware Version 0211.0213
Fan 1 9984
Fan 2 8960
Health check Information:
Status: Not Performed
Last Result: Not Performed
Last Execution: Empty
Next Scheduled Run: 2026-05-30 17:59:06 UTC
{master}
root@dc-tme-qfx5700-01-re0>
Both input and output current information is available from "show chassis power" CLI.
We don't have the proper metrology in our lab PDU to verify the accuracy of the Input counter.
Conclusion