Gaining ROOT Access will not impact performance at all...
It is what you do to Tweak the performance After Gaining Root that will have a drastic effect on performance..
But Always Remember that Performance and Power Consumption come Hand in Hand..
The Higher the Performance m, The quicker the power drain ... The Sloweemr the Performance The Slower the Drain...
It is why many people UnderClock their devices, rather than OverClock...
That being said, Yes you can expect some Performance enhancements with the correct Tweaks....
Using a Popular Benchmark software, i was able to get a performance increase of about 500% ..
The initial device at Factor specifications gave me 1/ 5th of the Benchmark from a Tweaked device...
The most effective twaeks are adding difference props inside the Build.prop file under /system
.Of course /system is not available to edit without Root Access.
To have a less slugish experience Without using root access, i suggest the following tweaks.
- Apps you don't ever plan to use.
Disable Apps that Can not be removed
- Open Storage Settings, and Click on Caches
Clear your Browser Cookies
- This one is a bit strange, but it works on many device's.
Disable Animations in Development Options
- Android displays Animations every single time you open or close something, this can Add up to 4 years of someone's life just waiting for Animations, it takes a lot of resources to load the animations and that drastically effects battery life and performance.
I've added some example screenshots of disabling Animations below.