NERSCPowering Scientific Discovery for 50 Years

Allocation Reductions

Projects that are not using their allocation at a certain pace may have time returned to the allocation pool of their respective DOE Office of Science Program to be redistributed to other projects. (ALCC, Director's Reserve, Exploratory, and Educational projects are exempt from this reduction.) We will be reviewing and removing both CPU and GPU Node hours. Projects are reminded that they may still run, in the Overrun queue, when they have exhausted their allocation for the year.

Allocation Year 2024

The following schedule will be used for Allocation Year 2024 (which runs from January 17, 2024 through January 14, 2025).

We will be using the forecasted computer usage values entered in the AY 2024 ERCAP requests. If you selected "I plan to use resources consistently throughout the allocation year", then your quarterly usage was set to 25% usage per quarter. If you selected "My usage will vary throughout the allocation year", then we will use the percent of usage you entered for each quarter. 

On April 17, 2024:

  • We will calculate the Expected Usage as: Expected_usage = initial_allocation*Q1_pct_in_ERCAP for Q1
  • Then if the actual usage is less than the Expected usage, we will remove time using the formula: 
    • If usage<expected_usage, reduce by 0.5*(usage-expected_usage)
  • For example:
    • If the Initial Allocation is 1000 Node hours and the Q1 % in ERCAP = 25%, then the Expected Usage = 250 Node hours
    • If the Actual Usage is only 50 Node hours, then the amount removed will be: 0.5 * (50 - 250) = 0.5 * (-200) = -100 Node Hours

This reduction scheme will apply to both CPU and GPU allocations, but handled separately (e.g., a project that has charged 10% of its CPU allocation but 20% of its GPU allocation, the amounts removed will be adjusted accordingly).

NERSC will accept requests for exemptions from the first quarter reductions only. Project Principal Investigators, PI Proxies or Project Resource Managers can request exemptions by creating a ticket at https://help.nersc.gov and include justification for the exemption. They must submit the request at least one week before the reductions are scheduled to take effect. 

On July 17, 2024:

  • The calculation for the Expected Usage for the 2nd Quarter: initial_allocation*(Q1_pct_in_ERCAP + Q2_pct_in_ERCAP)
  • Then if the actual usage is less than the Expected usage, we will remove time using the formula: 
    • If usage<expected_usage, reduce by 0.5*(usage-expected_usage)
  • For example:
    • If the Initial Allocation is 1000 Node hours and the Q1 % in ERCAP = 25% and the Q2 % in ERCAP = 25%, then the Expected Usage = 500 Node hours
    • If the Actual Usage is only 100 Node hours, then the amount removed will be: 0.5 * (100 - 500) = 0.5 * (-400) = -200 Node Hours

On October 16, 2024:

  • The calculation for the Expected Usage for the 3rd Quarter: initial_allocation*(Q1_pct_in_ERCAP + Q2_pct_in_ERCAP + Q3_pct_in_ERCAP)
  • Then if the actual usage is less than the Expected usage, we will remove time using the formula: 
    • If usage<expected_usage, reduce by 0.5*(usage-expected_usage)
  • For example:
    • If the Initial Allocation is 1000 Node hours and the Q1 % in ERCAP = 25% and the Q2 % in ERCAP = 25% and the Q3 % in ERCAP = 25%, then the Expected Usage = 750 Node hours
    • If the Actual Usage is only 150 Node hours, then the amount removed will be: 0.5 * (150 - 750) = 0.5 * (-600) = -300 Node Hours