ASRock Z170A-X1/3.1

Welcome to the forums.

No, 100 series chipsets do not support quad channel RAM. That is only supported on the socket 2011 platform.

Overclocking on the Z170A X1/3.1 should be solid. The only place I can think of you will run into issues is more extreme overclocking using very high (for the platform) voltages as the power design of the X1 is less competent than a higher spec board. For casual overclocking on an air cooler you should be able to achieve more or less similar results to a higher specification board. I must add though that a large part of overclocking potential comes from the CPU itself.

A more unfortunate CPU (overclocking wise) will overclock better on a higher end board due to better power delivery and likewise a higher end board will allow you to milk a little more out of even a good CPU.

The thing is, if you are buying an entry level board, you will probably be using air cooling or at most a budget AIO water cooling solution in which case you will likely reach thermal limits on the cooling before you reach the voltage limits of the entry level board, at least in most situations. While you may not get quite as much out of an entry level board as you would a premium one on the same CPU the question is simple:

Is the cost of a higher end board to get ~100-200mhz more from your CPU worth the price difference to you?

Especially when there is no guarantee that the higher end board will achieve a higher overclock at all, the CPU may simply not be up to it.

It is very difficult to give definitives when it comes to overclocking due to the sheer number of variables. A poor quality PSU could result in significantly lower overclocks, a poor overclocking CPU could also result in low overclocks as could insufficient power regulation from the motherboard. Overclocking, even on high end componets, by and large comes down to luck. You can increase your chances but it adds significant cost to the system:

1. High end board + $50 - $300 depending on how high end you go

2. High end PSU + $100 or more over the cost of a budget decent brand 550w

3. Pre Binned CPUs (available from some online stores) + a lot

At the end of the day most of these measures are only worth it for enthusiasts. The X1/3.1 should allow a decent overclock on an i5 6600k or i7 6700k allowing you to squeeze the extra value out of the extra you pay for a K class CPU. If you want actual figures you would have to look for reviews on the product as I do not own one so cannot provide them.

I hope this answers your questions.