Safe Overclock for ASUS R9 270X DirectCU II

[NomBom]

Hi guys, my graphics card tends to crash in some games when i turn up the settings so I just want to overclock it but I don't really know how to. Ive got msi afterburner and i tried boosting the clock speed and memory speed but it crashed so if anyone knows what a good overclock is for the reference 270x that'd be great. Thanks.

 

[chizrah]

https://www.techpowerup.com/reviews/MSI/R9_270X_Gaming/27.html
In this article your card managed a stable 1245 MHz and 1555 MHz for GPU and Memory respectively.