Crash could be due to various possible causes. 790 is a relatively stable business platform pc. What is spec and what strange logo do you see?  If your crash is reproducible and only occurs during gaming, then it may be related to gpu and not memory or chipset.  
I have a dell optiplex 790 and I was just playing a game and all the sudden it restarted, this time it showed a boot logo I have never seen before, then it went back to the normal boot logo I'm used to seeing, if anyone could tell me what the issue is that would be good, thanks.
My pc just restarted randomly