I will like to second the fact that this cards are shit, the MSI ARMOR's. Their performance vary across the board and I know this because I've been mining with 21 of this, 7 per rig, all with different memory and batch production dates. I can't remember when last I put the second rig on, I think the production batch does matter as the quality of chips would definitely depict the performance of the card. Anyone of them could start crashing the rig randomly, I've tried all I can at this point, but will soon get back to the rig that's not running.

They second rig runs, but would but as soon as you have an overclock and undervaluing that works with mining ETH without any issues, the moment you try to mine something else, you gotta find what works with that coin you want to mine.

Other then other hand, I have the ASUS STRIX ROG RX 570's too, the rigs never shuts down and all cards give the same hashrates, give or take .500mhz max different. All doing 29 even with undervolt. So, definitely MSI cards are shit regardless of the memory chip, it's just based on pure luck and or the production batch.