Johnsmith45

Thank you guys for your help. It turns out my i7 9700k died. Possible due to too much thermal paste. Buying a core i9 9900k seems like a good idea. I'm gone do that.

ITX advantages and disadvantes:
Advantages: smol Disadvantages: More expensive than average sized components, losing out on features, more limited component selection, worse cooling, and very little expansion options mATX advantages and disadvantages
Advantages: slightly smaller than ATX (barely, not really enough to be worth talking about most of the time. Disadvantages: Very little good motherboard options. There are some good board options for this size, the Maximus XI Gene, Z170M OC Formula, the upcoming Crosshair X670E Gene, etc. are all awesome motherboards, but most of the time the only mATX boards you'll find are where the board vendor doesn't want to spend the extra money on the 2.5" of PCB space.  If you don't need a super small computer, I don't see a reason to go for an ITX rig. It's a good option if you want more desk space or for a system to be super
 
mATX, on the other hand, is the form factor that just doesn't really matter. It's basically ATX but a little shorter. I don't mind it, but I also wouldn't really aim for it. 

I have a bunch of ITX builds, love them, and would not build another ATX system unless I have absolutely no way to accomplish what I need to without doing so. That's my preface to the below. I love ITX and have no interest in building any other form factor.
 
mATX
Advantages:
Smaller than ATX Some expandability Lots of cases Disadvantages:
The "redheaded stepchild" of form factors Motherboards tend to be lower-end Most cases suck A compromise in every way ITX
Advantages:
Compact and can be made absolutely tiny Easy to transport Lots of good looking cases Motherboard tend to be higher end Disadvantages:
Not much expandability The below can all be summed up as follows: much more expensive Components cost more Cases cost more Power supplies cost more If you go with the cheapest stuff you can find to cut costs (ATX power supply, Core V1 case, etc), you wind up with something almost as big as an mATX build, but only one PCIe slot to show for it.

ITX, at least ITX done well isn't the kind of thing you do if you just need a computer. Its an additional enthusiast option on top of just building computers done for either the necessity of a compact PC or in many cases, the fun of it. Packing as much power in as small a space as possible. Its not for beginners (though recent cases like the NR200 kind of buck that trend to a degree) and as stated above, parts are generally all higher and and compact, which translates to more expensive. It can be done cheaply but.. its usually kind of crap. 
 
"Worse cooling".. I mean that's debatable, we're able to do quite amazing things in the ITX space these days, that entire point is quite literally one of the main reasons people do it in the first place. 
 
Could I have put my 5800x and 3090 in an ATX case? Sure, but I find that boring and i've built plenty of ATX systems already. Fitting it all into my Meshlicious, undervolting and overclocking it and having it run well under expectations temperature wise, that's what I find enjoyable in building PC's these days. 
 
Back in 2014 I was wheeling my Cooler Master HAF-X into a LAN party on its freaking wheels and a wheel broke.. from that point forward, ITX.