Questions
Q1
Why TZ68K+ running with i5-3570K CPU will not be able to set CPU ratio over x38?

i5-3570K Ivy Bridge CPU will be able to run full OC function on Z77 chipset motherboard with latest ME 8.0 BIOS. CPU ratio has no limitation lock.

Z68 chipset will not be able to support it, due to Intel chipset spec limitation.