Full system crash after playing ONI for ~20-30 minutes

DXdiag states there where some problems with windows update. Maybe something gone wrong there, but thats only a guess.

Do you have a output.log from ONI?

You say, the computer completely shuts down? Not only the game crashes? 

This may be a problem with your RAM. ONI wants huge amounts of RAM (up to 12-14GB). Other games you tested may be a bit more decent here. So, if there is a problem with your RAM, you may not encounter this with other games. You may run a check on your RAM.

In general, if your computer goes into hard shutdown, its 90% the hardware. It may also be the power supply, because ONI drains hard on the CPU. 

I can´t, and wont rule out a problem with ONI, but it looks like a hardware problem, or something windows does.

I wouldn't be too surprised if there was a Windows Update issue.  I don't really keep up on it directly (relying on the auto update 'feature' of Win10), so I'll check that out.

Unfortunately, it's not generating an output.log file.. I've looked for it twice but it never seems to be there.  

Really??  12-14GB?  The system reqs on the Steam page say the minimum required is 4GB.. I've only got 8GB in my system.  Is that something that COULD happen if your colony gets maxed out in size?  Or is it something else?

Wow.. The system reqs say it requires a dual core 2Ghz CPU, mine is an 8-core 3.5Ghz.. Is there any way to monitor what the game is trying to ask for?  Or any settings maybe I can try to alter in the game that will prevent it from pulling that much from the CPU/RAM?  Sorry for the (probably really basic) questions, I'm just not sure what to do.

The system requirements are oooooold, and it has been mentioned here in fhe forums they should change it. A dual core cpu is no longer fine to play ONI beyond the start. 

Your CPU is also rather old, but the 8 cores could make that even. You just have to try. As for the RAM, 8GB should work. Maybe the system will start to swap at some point, but thats not the real problem. You should avoid to keep some other programs running while playing. A browser for example can use 2-6GB all on itself. 

The game shouldn't be able to crash the entire system. One thing to look out for is the CPU temperature. Try measuring it and see if it gets too hot while playing for extended periods of time.

1 hour ago, SharraShimada said:

Your CPU is also rather old, but the 8 cores could make that even. You just have to try. As for the RAM, 8GB should work. Maybe the system will start to swap at some point, but thats not the real problem.

The only way any of this could cause crashes would be a full HD, which would prevent windows from using swap space. The rest would affect FPS, but windows shouldn't be able to crash due to low FPS.