Having a hard time getting my multiplier to lock. I've been thru all the CPU options I can think of, and just can't seem to find one that does the trick. I'm checking it with CPU-Z(current version), it's fluctuating constantly. I read that this chip (i5 6600k) is unlocked and just thought that meant the multi could be raised as far as one wanted. Am I wrong there??? If I OC at all I do see those changes in BIOS but not in windows 10, CPU-Z, or E-Leet. Is this just an issue w/ Win 10 programs not being up to par yet and the clash w/ these new boards and chips? I was able to load and older version of CPU-Z and did see the Core Speed holding steady however, most of the info wouldn't fill in leading me do doubt it's accuracy. 
System Specs
Evga Z170 FTW BIOS rev 1.04
i5 6600k
32GB Mushkin Redline DDR43000 (15-15-15-35) 4 x 8gb
Corsair 1000wt PSU
Crucial CT240M500 SSD
2x GTX 560....def in need of an upgrade there :)
 
Thanks for any insight one can pass on in advance... 
Pearhead

Thx... will try when I return home later. I tried each of them individually but not sure if I tried them together... thx again for the reply!

Try this from Intel for stress and stability testing. It is the only utility approved by Intel for stress testing their CPU and it's Windows 10 compatible:
http://www.intel.com/content/www/us/en/motherboards/desktop-motherboards/desktop-boards-software-extreme-tuning-utility.html
 

Does XTU show fluctuating clock speeds in the monitoring graph?

The Z170 is a new platform. Check with support to see if it is a known issue or if they can recreate the issue in the lab. Just submit a support ticket with your question and see what they say.

Sorry for the long overdue update. I was able to get my multiplier to lock under a Win 7 environment by just turning off EIST and C-states. However, under Windows 10 not at all. In BIOS when I disable EIST, I loose my ability to OC.(Only shows one pull down tab under the cores). When it's enabled(shows all 4 cores) I can OC and my Mobo does save the settings but my multiplier still fluctuates. My current support ticket I have going has raised the issue of my memory and or a possible bent pin, and I have not checked the pins yet. I'm running a set of Mushkin Redline DDR43000 (15-15-15-35) 4 x 8gb, In XMP mode w/ voltage and timings on AUTO. Support ticket also raised the issue of a the z170 platform having a memory limitation of 2122mhz. i'm running DDR4 3000., and have noticed it's not showing it's full speed in CPU-z or eleet. CPU-z lists each stick as DDR4-2133(1066mhz), yet their running in XMP mode at 1500mhz 1:30 Ratio 15-15-15-35. Starting to feel like i have a memory issue... thanks for any insight that can be passed my way... is there a list for supported memory i've overlooked somewhere???