How to increase performance of ASUS Zenfone 5?

[rocket4929]

Recently I have bought an ASUS Zenfone 5 after reading positive reviews of it being performance-wise (high FPS on high-end games such as Asphalt 8, MC5) but as I try these games, it ran like hell (sluggish, low FPS). I immediately thought that they had some tweaks with their phones or more likely, custom ROMs. Can anyone tell me this tweaks or ROMs that increase the Zenfone's performance? Any reply is greatly appreciated.

 

[hang-the-9]

Reviewers would not use any custom ROMs in reviews unless they say that in the review.

I'd try a factory reset and install the game again and check it.

There is also this note from a review, if you don't have the 2 GB model you may have issues, and check for any updates from ASUS and your service provider.
"Editors' note: After I encountered sluggish performance in my initial ZenFone 5 review model, Asus sent us a new unit with updated firmware and 2GB RAM (the retail model sold in Singapore). Due to the improved performance that rendered the previous issues moot, I've updated this review and the score accordingly."