CPU Rate Limit
CpuRateLimit is a sandbox setting in Sandboxie Ini, available since Sandboxie Plus 1.17.5. It configures an integer CPU-rate percentage from 1 through 100 for the Sandboxie Job Object.
Usage
Syntax
In this example, Sandboxie configures a 25% hard CPU-rate cap for the Job Object. Internally, the value is passed to Windows as CpuRate = 2500 because Windows represents the rate as the percentage multiplied by 100. Users should configure the percentage directly; 25 means 25% and 100 means 100%.
Collective CPU Limit
The limit applies collectively to all processes assigned to the same Sandboxie Job Object. If several sandboxed processes consume CPU simultaneously, they share one CPU-rate budget; each process does not receive a separate 25% quota.
When the Sandboxie Job has no parent Job with CPU-rate control, the percentage represents a portion of the processor-cycle capacity of the entire system. If it is nested under a parent that also has CPU-rate control, Windows calculates its rate relative to the immediate parent's allocation.
Sandboxie enables the Windows JOB_OBJECT_CPU_RATE_CONTROL_HARD_CAP policy. When the Job consumes its permitted processor cycles for a scheduling interval, Windows stops scheduling its threads until the next interval. This throttles the processes rather than terminating them and is not a processor-affinity restriction. The underlying Windows mechanism is available starting with Windows 8 and Windows Server 2012.
Job Object Requirements
CpuRateLimit affects only processes assigned to Sandboxie's Job Object. Sandboxie skips that assignment for affected processes when NoAddProcessToJob=y, NoSecurityIsolation=y, or OpenWinClass=* is configured. AllowBoxedJobs=y does not itself disable the Sandboxie CPU-rate limit.
The rate is configured when Sandboxie creates its Job Object. If that Job still has active processes, Sandboxie reuses it, so a configuration change may not take effect until the current Job is no longer in use and a new one is created.
In SandMan, this setting is available under Sandbox Options > Security Options > Job Object as Total CPU Rate Limit (%). The field accepts values from 1 through 100 and shows unlimited when the setting is not configured.
CpuRateLimit controls how much aggregate processor scheduling capacity the Job Object may consume. To restrict where sandboxed processes may execute, see CPU Affinity Mask. The two settings can be used together; the percentage is not recalculated solely from the processors selected by the affinity mask.