4.4Ghz should be very easy by manually changing a few things.
- CPU Vcore = 1.280v
- CPU Ratio = 44
Try just the above with XMP disabled and see what happens.
When you enable XMP these voltages will increase automatically and usually above what is required.
- VCCIO = 1.15v
- CPU System Agent Voltage = 1.15v
This will be ok for 2800Mhz
A long time ago I stopped using a Gigabyte Z170X-UD5 TH board with my 6700K CPU so I cannot be precise on the exact wording for your BIOS.
When you set the Vcore to 1.280v, this will drop when the CPU is under load / P95.
For 4.4Ghz you need at least 1.25v.
The CPU will also down clock when under load so you need to adjust the power limits.
- CPU current limit = Max out
- Turbo boost long wattage = Max out
- Long Time = Max out
- Turbo boost short wattage = Max out
- Short Time = Max out
Use the Intel XTU software to determine the above options, change in bios to see what changes in the XTU software.
https://downloadcenter.intel.com/download/24075/Intel-Extreme-Tuning-Utility-Intel-XTU-Your BIOS lists these as the following, MIT section
- Power package limit1 (Watts)
- Power package limit1 (Time)
- Power package limit2 (Watts)
- Power package limit2 (Time)
- Core Current Limt (Amps)
Type 9999 for each one to max out.
Other than those options, the rest is up to you.
Load Line Calibration for the CPU Vcore can help stabilise the voltage drop.
And if you don't have a reasonable cooler your temps will shoot past 80 degC in a Prime95 blend / max power test @ 4.4Ghz.
