Unstable overclock. Just because one game crashes and another doesn't, that doesn't mean it's DayZ, it's just your overclock dude.

Cant you read? I looked up the right and perfect overclock settings for my graphics card, even if it is just 1 percent overclock it crashes. God

And you don't know what you're talking about. There is NO perfect overclock for a card, "Every Card Is Different!". Every single card is different, they can be the exact same make and model but some will overclock very well, some will not. If you overclock just 1% more and it crashes, you are obviously right on the edge, so "Lower" your overclock a little bit and try running DayZ again. If it's fine when your card has a lower clock, then it's obviously you and not DayZ.

I know that every card is different, but why is only DayZ crashing?

Because all games are also different, they push your PC in different ways. I know that exactly what my "Maximum" overclock is for my CPU, if I enable my maximum overclock it will pass a Prime95 stress test no problem.... BUT, I get BSOD in some applications and games, because they push my CPU in different ways.

Seriously, just try lowering your overclock a little bit. Also check your temperatures.

I already went back to normal settings with no problems. Its just kind of annoying

Of course, everyone want free extra power from their PC :)
But that's what I'm saying, if it works fine when you are at stock clock, then it's the overclock causing the issue.
If your overclock is, as an example, 1200MHz and your stock clock is 1100MHz, then lower your overclock a little bit to 1150MHz. You don't have to go back to stock clock and default settings.
Also, make sure your temps are not exceeding the recommended maximum which is I think around 85c for your card.

Temperatures are, however, not higher than 50°C, and DayZ crashed as I said even with 1 % overclocking ._.

Sorry, I misunderstood. I thought you meant 1% higher overclock caused crashing.
Have you tried stress testing your overclock to check stability?? Also running other games?

System runs normal when I overclock like it should be fine.
Other games not available at the moment, refurbished windows some days ago.

push

Dude, I'll say it again. You need to "Stress Test" your overclock and play other games before you can say it's DayZ causing it.
Stress test your CPU as well because DayZ is very heavy on CPU usage.
Sometimes a graphics card can be unstable even with a 1% or 0.1% overclock, some cards can be unstable even at Stock clock straight from the manufacturer, there is no reason for DayZ to cause the issue.

Use these programs:
Unigine Valley Benchmark (Run it constantly for at least 1 hour)
3DMark 11 (Run it constantly for at least 1 hour)
3DMark Fire-strike (Run it constantly for at least 1 hour)

Does it do this?

http://feedback.dayzgame.com/view.php?id=18684

Not really it is just a random crash

Hi Tombo,
sadly, we cannot guarantee full functionality on overclocked hardware. If the game works fine when every thing is set to default values, I will close this ticket.
I am going to talk about this to other developers, but I cannot promise you that the issue will be getting fixed.
Thank you for understanding,
Andy

Yes, everything is fine on default.
Thank you.