ios 7 iphone 4

What doesn’t change

iOS 7.1 doesn't perform any differently in CPU, GPU, or browser-based benchmarks than iOS 7.0. Apple sometimes takes these medium-sized updates as an opportunity to further optimize Mobile Safari's JavaScript engine, but that's not the case here.
You're also missing the same iOS 7 features that you didn't get in the 7.0 release, a list which we'll reprint here for your convenience alongside all of the iOS 5 and iOS 6 features the iPhone 4 didn't get.

• 3D Flyover or turn-by-turn navigation in Maps
• Panorama mode or Filters in the Camera app (filters can still be applied after the fact in the Photos app)
• AirPlay Mirroring
• Siri
• AirDrop
• A number of the new graphical effects present on all other iOS 7 devices. These include translucency effects throughout the OS, live wallpapers, and the parallax effect used on the Home screen

Aside from these items, the general UI tweaks introduced by iOS 7.1iphone4  are all present on the iPhone 4—we'll go into more detail in our full review (coming soon).

Performance

Luckily, there are plenty of things Apple can do to speed up iOS 7.1 that won't show up in benchmarks. The worst speed-sapping problem that afflicted iOS 7 was its flashy, overlong UI animations, which were sometimes used to cover up application load times but more often added unnecessary seconds to the amount of time it took to do anything. This was true whether you were using an old iPhone 4 or a brand-new iPhone 5S freshly liberated from its packaging. These animations could sometimes double the amount of time it took to launch common apps on the iPhone 4 compared to iOS 6.1.3 running on the same hardware. Even worse, you usually had to wait for these animations to complete before you could do anything else, which sometimes made iOS 7 feel less responsive than previous versions had been.
iOS 7.0.3 was a first step toward fixing this problem for people who knew which settings to tweak. Going into the Accessibility Options and toggling "reduce motion" originally just disabled the parallax effect used on the home screen and throughout the operating system, but version 7.0.3 also disabled the sweeping animations used to transition from app to app. In its place was a crossfade effect that was less flashy but also demonstrably faster.
iOS 7.1 solves the problem for people who don't tweak their devices' settings or for people who like the way the animations look but not how they feel. Animation durations have been shortened noticeably throughout iOS 7.1, and toggling "reduce motion" is now purely cosmetic. To show how this speeds up even the slowest of Apple's phones, we re-ran our application launch tests under iOS 7.1 and compared them to the results from iOS 6.1.3 and 7.0.
The numbers below measure the time between when the app icon is tapped and when the app becomes ready for user input. Each app's launch time was measured three times and averaged. The apps were force-quit using the iOS multitasking interface between runs.