Set up my EVGA 1070 Ti this afternoon (Micron memory

)and adjusted settings to 80% TDP +200 Core +600 memory. Ran fine with about 525-530 sol/s for about 45 mins then artifacted on me on and crashed system as my monitor was hooked up to this. This something I should RMA if it happens again?
No - it just means you didn't get lucky in the silicon sweepstakes on your memory or your core - OR you have poor cooling for the card and you managed to overheat it.
What temp does the card get up to after 5 minutes or so?
I have no idea what memory type my EVGA SC 1070 ti cards have, as I don't run them on Windows so no GPU-Z to easily tell without disassembly.
Not sure why "in game" was mentioned in some of the replies, OP didn't say anything about gaming on the card.