Pentium G3258 Anniversary Edition
Batch # 3412B733
Asus H81M-PLUS
BIOS Version 2104 08/08/2014
Arctic Cooling Alpine 7 Pro HSF
800 - 4000MHz (8x - 40x)
VCore 1.065V
PNY GeForce 650 GTX 1GB DDR5 video card (Note: use of processor graphics substantially reduces overclocking potential)
Prime95 stable in Windows 7 @ 78 degrees C (tested for 30 minutes)
Idle temperature in Windows 7 @ 38 degrees C
maximum power consumption approximately 35W according to HWMonitor (approximately 8W at idle)
Most settings are set to Auto, except for the following:
> Ai Tweaker:
Sync All Cores
CPU Core Ratio Limit - 40
Min CPU Cache Ratio - 40
Max CPU Cache Ratio - 40
DRAM Frequency - DDR3-1333MHz
EPU Power Saving Mode - Disabled
Extreme Over-voltage - Disabled
CPU Core Voltage - Manual Mode
CPU Core Voltage Override - 1.065 (default VCore was 1.058V)
DRAM Voltage - 1.50V
> Ai Tweaker > DIGI+ VRM:
CPU Load-line Calibration - Auto
CPU Fixed Frequency(KHz) - 250
CPU Power Phase Control - Optimized
CPU Power Duty Control - T.Probe
CPU Current Capability - Auto
> Ai Tweaker > CPU Power Management:
Enhanced Intel Speedstep Technology - Enabled
CPU Integrated VR Fault Management - Disabled
CPU Integrated VR Efficiency Management - High Performance
Power Saving Level 1 Threshold - 0
Power Saving Level 2 Threshold - 0
Power Saving Level 3 Threshold - 0
> Advanced > CPU Configuration:
Intel Adaptive Thermal Monitor - Enabled
Boot Performance Mode - TURBO PERFORMANCE (Note: Windows will not let the CPU run over 3.2GHz default unless you set this to Turbo)
CPU Power Management Configuration > EIST - Enabled
Observations:
First of all, I'm not an overclocking expert. I do not understand all of the voltage options. Second of all, when I received this motherboard, the BIOS was out of date and it would not support the Pentium G3258 (or other "Haswell refresh" CPUs, presumbly), so I used an older Haswell CPU (Celeron G1830) to update the BIOS. The motherboard wouldn't POST, but no, that did not mean the motherboard was "dead". Updating with a USB flash drive in DOS was not sufficient. My guess is that the Intel Management Engine (ME) was not updated. I updated the BIOS to the same version in Windows, and then the motherboard was able to boot up with the Pentium G3258.
The BIOS was acting weird, in my opinion. Some of the CPU options related to Turbo Mode appeared and disappeared, depending on which other options were enabled. I would have preferred to see them greyed out if they were pre-empted. Turbo mode MUST be enabled to permit overclocking. As I understand it, overclocking with a non-Z chipset is achieved by running the "K" CPUs in Turbo mode to achieve higher clock multiplier settings. I was concerned about excessive heat, so I kept Speedstep and some of the other power saving technologies enabled. The CPU appeared to be limited to 4.2GHz @ 1.24V (it would not boot into Windows at 4.3GHz) and it was actually Prime95 stable at that speed and voltage, but the CPU was getting too hot in my opinion (around 85 degrees C). CPU Q-Fan Control was enabled using the "Standard" CPU Fan Profile. A better CPU cooler or more aggressive cooling with the one I had might have helped (e.g., running the fan at full speed all the time), but I want a quiet system that doesn't expel a lot of heat into my room, so I feel that it is better to reduce the CPU speed and voltage.
In case you didn't see my note above, Boot Performance Mode MUST be set to Turbo Performance. When I first tried overclocking this CPU/motherboard combination, the CPU ran at its default speed in Windows instead of using the multiplier I selected. I did a Google search to find a solution to this problem, and I didn't see it posted anywhere else. When the machine boots up, the CPU speed is reported as 3208 MHz. When you're in Windows, the multiplier setting will vary, as it should. CPU-Z reports that my CPU was running at 4.0GHz under full load and idling at 800MHz.