CPU Affinity Mask
CpuAffinityMask is a sandbox setting in Sandboxie Ini, available since Sandboxie Plus 1.13.5. It restricts sandboxed processes to selected logical processors by applying a processor affinity mask as each process initializes.
Usage
The value must be hexadecimal and begin with 0x or 0X. Each set bit allows the corresponding logical processor. In this example, bits 0 and 1 are set, so sandboxed processes may run on logical processors 0 and 1. Logical processors do not necessarily correspond one-to-one with physical CPU cores.
Current Limitations
The current Sandboxie implementation supports logical processor indices 0 through 31 only. Bits for logical processors 32 and higher cannot be configured with this setting, including on 64-bit Windows.
Sandboxie exposes one affinity mask but no processor-group selector, GROUP_AFFINITY setting, or CPU Sets setting. On systems that use multiple Windows processor groups, the mask is therefore subject to Windows' single-group affinity semantics and cannot explicitly select processors in another group.
If Windows rejects the requested affinity mask, Sandboxie currently does not terminate the process because of that failure. If CpuAffinityMask is not configured, Sandboxie does not apply this setting's processor-affinity restriction.
CpuAffinityMask controls where sandboxed processes may execute. To limit their aggregate processor scheduling capacity, see CPU Rate Limit. The two settings can be used together.