Z370 now or B370 later and cause of budget i3 8100 now but with 2,4ghz or 3,2ghz memory

First of all, the price of memory is higher right now than it has ever been, BUT it is going to go UP and not down, so if you want 16GB, get it now. There are two reasons for that.

First, you should always buy the amount of memory you want in a matched set because there are never any guarantees otherwise that they will play nice together and run in dual channel or even WORK together, even if the part numbers are the exact same. As I just showed somebody yesterday there are even very recent G.Skill ripjaws modules using identical part numbers but one production run has 4gb single sided chips while the other run has dual sided 8gb memory chips. Now, these MIGHT work together, but there is always a chance, and more and more it's a good chance, that unless they've been factory tested to run together, they may not.

Second, you will probably pay about 20-30% more for them next year than now. If you want 16GB I would not even wait six months or even until you buy the rest of your components, I'd buy them now while they are less expensive than what they are going to be soon.

https://epsnews.com/2017/09/22/expect-tight-dram-supply-2018-possible-oversupply-nand-flash/


If you already have memory then I'd say use it. Even if it's only 2133mhz memory, the performance difference between that and anything up to 3200mhz is not earth shattering, even on AMD systems that show some benefit from faster memory it's not THAT impressive that I'd be willing to scrap the memory I already had and buy a whole new 16GB kit for it.


Usually, almost always, the lower end chipsets like the H and B series boards DO have less power consumption because on enthusiast boards they are primarily concerned with performance, not efficiency, so that MIGHT be worth waiting for.

Another factory you might want to consider before deciding to do ANY of this, is this:

http://www.tomshardware.com/news/intel-bug-performance-loss-windows,36208.html


I personally don't think the performance hit is going to be dramatic, but it is PROBABLY worth waiting a week or two to see how this unfolds before pulling the trigger on anything.

Also, if pinching every last penny, so to speak, when it comes to power consumption, is a priority, then you should absolutely be more concerned with what power supply you are running and might really want to focus on getting a very high quality Seasonic, Corsair or EVGA unit (AND not all of them are great, so specific model is important) with either a platinum or titanium 80plus rating since those are more energy efficient than other models.

I'd say going with a Gold rated unit at minimum would be a good idea but if it's that critical then Platinum or Titanium would be almost necessities since the difference in efficiency will probably outweigh any power efficiency differences you'd see from one motherboard chipset to another as you first mentioned.