SAGV (System Agent Geyserville) is a way by which they SoC can dynamically scale the work point (V/F), by applying DVFS (Dynamic Voltage Frequency Scaling) based on memory bandwidth utilization and/or the latency requirement of the various workloads for better energy efficiency at System-Agent. Pcode heuristics are in charge of providing request for Qclock work points by periodically evaluating the utilization of the memory and IA stalls.
SA Speed Enhanced Speed Steps (SA-GV) and Gear Mode Frequencies
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DDR Maximum Rate [MT/s]
SAGV- MaxBW/ lowest latency
|S || DDR4 || 3200 || 2133 G2 || 2666 G1 || 2933 G1 || 3200 G1 |
| DDR5 1DPC || 4800 || 2000 G2 || 3600 G2 || 4400 G2 || 4800 G2 |
- 12th Generation Intel® Core™ Processors supports dynamic gearing technology where the Memory Controller can run at 1:1 (Gear-1, Legacy mode) or 1:2 (Gear-2 mode) and 1:4 (Gear-4 mode) ratio of DRAM speed. The gear ratio is the ratio of DRAM speed to Memory Controller Clock.
MC Channel Width equal to DDR Channel width multiply by Gear Ratio
- SA-GV modes
- LowBW- Low frequency point, Minimum Power point. Characterized by low power, low BW, high latency. The system will stay at this point during low to moderate BW consumption.
- MedBW - Tuned for balance between power & performance
- HighBW Characterized by high power, low latency, moderate BW also used as RFI mitigation point.
- MaxBW/ lowest latency Lowest Latency point, low BW and highest power.