How to explain performance boost of application under iframe on Samsung mobile phone[chrome]?

Question

I'm developing an application that design to be inserted in side web-site via iframe.
Recently QA reported about notisable performance regression between prod and dev env in chrome (Sasmung S3)
During some researching I've defined that it's not a regression, mobile app works the way faster under iframe on this device in chrome browser.
I tested on different devices and seems that the such behaviour present only on Samsung devices (also tested on Samsung S7 edge, HTS one, Nexus 5).
On Nexus5 and HTS one there is no difference is iframe present or not.
How to explain such behaviour?

Answer 1

iframe forses GPU mode on mobile devices.