Intel® Core™ Ultra 200H and 200U Series Processors CFG and MEM Registers
| ID | Date | Version | Classification |
|---|---|---|---|
| 844345 | 01/29/2025 | 001 | Public |
(CORE_PERF_MIN_MAX_0_0_0_MCHBAR) – Offset 5b10
This register serves as an interface for OSPM (OS Power-Management) to request Min and Max performance for the most performing IA Core (E-Cores are not subjected to the interface and their perfomance will be selected by Pcode).
The interface will use a scaling factor to define unitless performance metric, as suggested in the ACPI spec's CPPC section:
Performance = frequency * core_scaling_factor , core_scaling_factor = CPC.nominal_performance / CPC.nominal_frequency
CPU will allow going below MIN_PERF_FOR_PL1 for some Cores due to V/F differeces, and in cases of energy optimizations (OS EPP, internal heuristics).
| Bit Range | Default | Access | Field Name and Description |
|---|---|---|---|
| 63:32 | 0h | RO | Reserved |
| 31 | 0h | RW | (VALID) Valid bit for both values. Must be set to '1 for the request to be valid. |
| 30:9 | 0h | RO | Reserved |
| 8 | 0h | RW | (MIN_PERF_FOR_PL1) Min performance request, to be used as performance floor for PL1 limit. |
| 7:0 | 0h | RW | (MAX_PERF) Max performance request. Value will be clipped by Pcode to be between CPC.lowest_performance and CPC.highest_performance. |