If your CPU temperatures aren't high, it's probably because the VRM on that board is terrible and can't keep up the power delivery. On Newegg, that is literally the cheapest Z370 board you can buy. For $10 more at the time of this post, you can get the AsRock Z370 Killer SLI/ac that has significantly more power phases and wouldn't throttle under load. Asrock advertises they use 45A rated chokes (which are really good on a budget board), I can't find any info from a quick search on that MSI board. Just from a quick look at the number of chokes, the MSI Z370-A Pro has 6 phases while the AsRock Z370 Killer SLI/ac has 11 phases. I'm not an expert on Z370 boards, I don't know how the phases get split up between CPU and other parts as well as if they are using doubling or not. Generally more chokes = better for overclocking and power delivery.

If you're still in the return period I would return it. I would only use such a board in a stock system for someone with a non K SKU. If you are going to keep it, you better get some serious airflow over the VRMs and not push it too hard.

 

Thanks for the reply but it turns out all i needed to do was set max turbo power limit short and max turbo power limit long to 150 in bios and that fixed my problem and I bought this board awhile ago and just now decided to overclock so returning probably isn't an option and I bought the board in store and it was the only z370 they had in stock (was around christmas time) so I just priced matched it online. Anyway thanks for your help!

 

setting the turbo limits is common, however as pointed out that is a entry level board and regardless of marketing, has less expensive components and will limit your OCing.

srly, screwing around with the VRM signal at that low of voltage already might to tell ya something.

just be safe.