Iphone 6 being incredibly slow

[iMore Question]

Hello, I have an iPhone 6 i recently got from a friend. Since I received it it has been INCREDIBLY slow like nearly unusable, its on ios 11.1.2, and i know the iphone 6 isnexactly the newest device but it shouldn't be this slow surely, even on 3D Mark I got a lower score than average, apps are slow to open and load, even pulling up the control center has a stutter and lag, along with unlocking the phone. Ive tried reinstalling IOS through itunes with no help, and have reset the phone a few times, but it doesn't seem to improve much,i'm just not sure could be causing this level of slowdown on a device like this thats nearly new software wise and inst a dinosaur hardware wise. Any tips or ideas or help would be appreciated, thank you.

 

[TripleOne]

The iPhone 6 is now 3 years old, and it is quite slow when running iOS 11.

 

[eve6er69]

I have a 6s and it has been running spectacularly it's whole life. I account that to not updating the os to too higher ones. I'm still on 10. With that said maybe you should take it to Apple and see if your processor is running properly. It is 3years old but if well taken care of it should last a few more years.