pc freezing while gaming

[phonycarrot]

So my problem. I built my pc about 6 months ago and for the last 2 months or so iv been having freezing issues it doesnt play the last sound on a loop or anything like that it just freezes requiring a hard reset even while idling. Yesterday I discovered that if I lay the pc on its side it doesnt freeze on idle, only when I load up player unknowns battlegrounds (havent tried any other games) and it only freezes when the match starts, It handles the loading just fine. My friend helped me narrow it down to either the mobo or psu but iv seen a couple of forums mention the same thing happening when the cpu dies too. So im wondering if someone with more experience knows a more accurate diagnosis. Iv already run memtest and multipal hard drive tests as well as defraging my hd, on top of running the fuzzy doughnut of death for my gpu which didnt freeze at all even at 4k. Iv even tried using msconfig to limit the number of processes that can run as well as fresh installation of windows os's 7-10


My specs are
Cpu: AMD FX 9590 (non overclock),
Gpu: Zotac GTX 1070 Amp Extreme
Ram: crucial 8gb 2x4 gb + unknown ram that came from my old alienware pc that has the same speed but were 2x3 gb that I removed
Cooler: corsair h100i v2
Case: Thermaltake versa n21
Hard drive: seagate 2tb fire cuda gaming ssdhd (baught new)
Psu: EVGA Supernova gq 1000w
Mobo: gigabyte 990-fxa-ud3-r5


Any feedback would be greatly appreciated

 

[Calvin7]

Memory manufacturers guarantee the rated specifications of any memory to be obtainable only in the kit it is sold in. If you are adding an additional set of memory, the memory may not be able to operate at rated specifications.

I suggest you install a single kit of 1866MHz memory.
G.SKILL Sniper Series 16GB (2 x 8GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model F3-1866C9D-16GSR
https://www.newegg.com/Product/Product.aspx?Item=N82E16820231627&Tpk=N82E16820231627