Help Back-grading Android

[Qualcomm_Inside]

I have a couple of questions about installing Roms and modding Android.

1: is it possible to backwards update versions of android?

Like my phone is really cheap, but it is running 5.1 lollipop so it is mostly up to date. However the hardware is not really able to handle that much OS. lol
Could I perhaps install a earlier version and give the CPU more resources?
Would this make sense? Is this safe?

I currently do not have root permissions on my device, but I'm thinking of testing this with another cheap phone that can be rooted.
If I root device, install let's say 4.4 KitKat on a phone that came with lollipop, would it be faster and smoother than this glitchy crap I have now? Would it be any less secure?

 

[chanchan05]

1. You mean downgrade. You'll get more Google search hits if you use the correct term.

2. Yes it's possible to downgrade but there are specific circumstances only where that can be done without bricking.

3. What phone model do you have and what OS version did it ship with? If it came with Lollipop out of the box, then a ROM with lower version of Android will be nonexistent. The lowest version a phone can be downgraded to is the one that came from factory.

4. There is no such thing as one for all Android installer. The ROM should be specifically made for the phone model.

 

[psionandy]

Unlike desktop pcs (or even Laptops) phones Roms are incredibly device specific...to the point where trying to put a Rom on for a different model in the same range would be disastrous!

If the Manufacturer of a phone, has released a ROM for a previous version of Android.. then yes it is possible that if you jump through the right hoops, in the right order, you can go back to a different version.

If you're running a really cheap (and generic) device, this really isn't going t o be possible as chanchan05 pointed out.