Nvidia DGX B200 - Managing N+N Configuration (IPMI)

NVIDIA DGX B200 User Guide
7.2. Managing N+N Conguration (IPMI)
By default, a system will boot with three power supplies. To achieve the safe operation of an N+N
conguration, you need to enable the power capping feature to limit the power consumed by the
system.
Get the System Power Limit
ipmitool raw 0x3c 0x80 0x05
The format of the response is c8 32. To convert this value:
(0xc8 + 0x32 << 8) = 0x32c8 = 13000
If the feature is disabled, a value greater than 12,000 is returned.
Enable PSU Redundancy Support
To enable the PSU redundancy feature, set the power budget limit outside the actual system budget.
The following example sets the power budget to 12 kW.
ipmitool raw x3c 0x81 0x05 0xE0 0x2E ∕∕Set 12 kW
Enable Power Capping Support
To operate the system lower than the maximum power budget the PSU can support, set a limit lower
than:
ipmitool raw x3c 0x81 0x05 <MSB> <LSB>
The following example sets a limit of 6 KW (0x1770):
ipmitool raw 0x3c 0x81 0x05 0x70 0x17
Querying the GPU power limit using Redsh API shows 562 W:
...
"PowerLimitWatts": {
"AllowableMax": 700,
"AllowableMin": 200,
"ControlMode": "Automatic",
"DefaultSetPoint": 700,
"Reading": 64.335,
"SetPoint": 562
}
...
56 Chapter 7. Managing Power Capping