Why are older iPad generations not compatible with newest iOS?

[Yebubbleman]

I manage iPads at my company for our electronic medical record system. Can someone explain to me why the older iPad (even iPhone) generations are not compatible with the latest model iOS software?

For example, I've spoken and read about too many people with iPad 1st and 2nd generation who said iOS 9 caused major issues with their iPad. I had an iPhone 4S that had major issues following the iOS 8 software update. Our company currently uses iPad's 4th generation and our EMR vendor requires us to update our iOS to be compatible with their application.

I just want to get some info so I can better understand why. Thanks for any help!

First off, only the original iPad isn't compatible with the current version of iOS. That iPad stopped on iOS 5.1.1 and almost four years ago. As for why the older currently supported iPads run terribly, it's because the software keeps getting more advanced which usually leads to bloat, which usually requires more muscle. This is why an original iPad Air running iOS 7 runs as fast as an iPad Air 2 running iOS 8. Similarly, an iPhone 6s or 6s Plus runs iOS 9 as fast as the iPhone 6 and 6 Plus ran iOS 8 and as fast as the iPhone 5s ran iOS 7. Each update makes things run slower.

That being said, if you are managing iPads and you're running fourth generation iPads, I'd start planning your rollout for newer models NOW. Don't start buying them now, but plan for what you'll need to do and when you'll need to do it. This next 9.7" iPad launch (whether it's called "iPad Pro" or "iPad Air") will be the perfect thing to switch to. Because odds are that your fourth generation iPads will either not get support for iOS 10 or will run it very poorly.