NP9380-S Mobo Overheating?

Lately my computer has been hard freezing during gaming (just about any game). I've got a slew of hardware test that I can run and everything has passed. My GPUs at their hottest get to about 88 C and my CPU hovers around 89 C. I have a 4800MQ and Intel stated that this version runs hotter than any of the other Haswells and that's quite normal. Speccy shows my MoBo however in the 50 C range at idle and I've seen it go as high as 90 C. I have configured my computer in every way possible to generate error logs but I just can't seem to narrow it down. I have ordered a chill mat but I'm worried that it may not be my motherboard overheating. All of this started about 3 months ago and it has slowly gotten worse. I'm worried that I'm going to burn up either my MoBo or my SSDs with as often as my computer has been freezing up. Any suggestions?

*Edit* I am also using a custom BIOS and vBIOS setup, could it also be a chipset or gpu driver issue?

 

You mentioned
"I have configured my computer in every way possible to generate error logs but I just can't seem to narrow it down."
Have there been any logs generated, it looks like no, but not for certain no.
Sudden shut downs are usually hardware issue, and most of the time from overheating but you temps seem low enough not to cause that.
Have you tried removing RAM sticks and just running off 1 at a time to see if they all cause the same shut downs.

 

Correct, the logs that are generated are not saved if the system crashes. I'm not having any BSODs, just hard freezes. I've run QA+Win64 and PC Check, everything passed. The only piece of hardware I haven't figured out how to test is my slave GPU. QA+Win64 only test the primary GPU. I did some tinkering and disabled all non essential devices in the device manager (Bluetooth, BD Drive, Card Reader, Nvidia HD Audio driver, and my touchpad). Oddly enough I haven't had any crashes since disabling these devices, but I never really used them prior. That's why I'm leaning towards my MoBo overheating when everything is enabled. I did try taking out a ram stick but my system idles at 4.2 GB usage. So any heavy gaming I do tends to crash after running for a few minutes because of low system memory with just 1 stick installed.

*Edit* Forgot to mention, I have 2x 8GB sticks of Corsair Vengeance under clocked at 2000Mhz. They're a 2133 set, but they run in my system stock 1866. I'm not an expert at overclocking so I'd rather not try. The lock ups occur no matter what clock rate.

 

Since the problem is slowly getting worse my guess would be something analogue, in that case it would point to the PSU.