My specs:
RX 580 8GB Gigabyte Aorus XTR
i5 6400
2x8GB RAM DDR4 @2133mhz
1TB HDD 7200rpm Toshiba
Asus H110M-C/BR
Now the problem is that i'm not getting the performance i should on some games, like ArmA 3 or CS GO and the problem seems to be that the card isn't being used at it's max. On CS GO or ArmA 3 the GPU clock never goes to it's max, on CS i'm getting 150fps on low and on ArmA 3 doesn't matter the setting max or lowest i only get around 30-40fps always, i've seem some people with similar issue on this forum but none seem to have got a propper fix. Hope someone can help me.
Recently i've done somethings -unsucefully- trying to solve this:
-Uninstalled MSI Ufterburner
-Reinstaled the drivers usind DDU
-Set GPU and memory clocks to dynamic on WattMan
None of this solved my problem.
Everything you say is very normal. No problem, I guess. When you run a game, it is normal for graphics card core clock speed to decrease. Excessive fall is not normal. Also, when you change graphics quality of a game, a different result cannot be achieved by you with some games. Because the processor is probably not enough for increasing FPS with some games.
Also, reason that GPU's boost core clock speed drops while a game is running is because graphics card has reached TDP limit.
The card at it max consumes something like 120w, on those games i said it doesn't go beyond 30w. I don't think it's normal for this card not to reach 60fps on Arma, and surely the i5 6400 isn't the problem.
30W power consumption is not normal with a game. 6400 processor is fine. But you may not get the FPS increase when you change the graphics quality in some games. This is because the processor. I can't comment on your example game (Arma).
I saw on other posts about this problem that using older drivers just fixed for some people, i just installed 18.3.4 but dindn't worked out for me... guess ill keep looking for something