Z170 Extreme4 Bios 3.20 + 3.40 Problems

sensi wrote: Thanks for the reply parsec, CPU is an i5 6600k and the RAM is 2x8GB G.Skill TridentZ 3200 CL16.

You probably have the TridentZ F4-3200C16D-16GTZ kit. I use a similar model in my ASRock Z170 board.

TridentZ memory at its rated speed (3000+ models) will certainly try to use more that 1.1V for the VCCIO and VCCSA voltages, with their XMP profiles.

What I think is happening is the new UEFI versions need to run memory training with high speed DDR4 memory. The default settings in DRAM configuration usually don't enable memory training.

In the UEFI, OC Tweaker, DRAM Configuration screen, at the very bottom, find the MRC Fast Boot option. Set it to Disabled.

Your memory is a Double Sided (DS) type of memory, that works best in the A1 and B1 slots, in case you don't have it in those slots now.

sensi wrote: Hello there, i encountered a Problem with the 3.20 & 3.40 Bios with VCCSA + VCCIO on my Z170 Extreme4 Mobo when set higher then 1.1V the PC won't start and gets a Boot Loop. With the old 2.90 Bios all is fine. So i think the Bios is buggy. Would be awesome if you could have a look @ it. Thanks for your Help :) Cheers, sensi

You are the first one to report this as far as I know. I don't have this board so I cannot test it myself.

What memory and CPU are you using?