How much faster is the iPhone 3GS than the iPhone 3G? How much difference does this speed boost make in actual use?

Apple formally declares the iPhone 3GS to be "up to twice as fast" as the iPhone 3G.

Although Apple releases no official specifications for the iPhone models, third-party teardowns indicate that the iPhone 3GS has a significantly faster ARM Cortex A8 processor (600 MHz up from 412 MHz), and a faster PowerVR SGX graphics processor as well as twice the RAM (256 MB up from 128 MB).

Consequently, it would not be unreasonable to expect the iPhone 3GS to be "up to twice as fast" but only benchmarks and real-world tests can reveal the speed difference for sure.

Benchmark Performance Overview

For a solid general overview of the performance differences between the iPhone 3GS and the iPhone 3G and other iPhone and iPad models as well as the iPod touch line, Everyi.com's own Ultimate iComparison makes it quick to compare side-by-side Geekbench benchmark averages for hundreds of possible performance comparisons.

Specifically, the Geekbench benchmark shows that the iPhone 3GS is a massive 107% faster than the iPhone 3G.

Other Test Results

Geekbench provides a convenient overview of overall performance, but other benchmarks and real-world tests can be useful for a well-rounded viewpoint.

As part of a longer review, Engadget shared:

For our oft-used phone actions -- flicking through homescreens, calling up search terms in Spotlight, scrolling through long lists -- we definitely felt like the 3GS was snappier than its predecessor. It wasn't like the doors were flying off, but there was a noticeable bump in speed, particularly when it came to initial data loads (how quickly you see content pop up within an application). When it came to opening apps which pull lots of that kind of content, like Contacts, Calendar, or Messaging, we saw an even more noticeable improvement. Comparing the 3G and 3GS side-by-side yielded small but absolutely palpable differences -- the 3GS does seem to eliminate quite a few of the hangs we find maddening as we go through our day. It's not the perfect salve, but it's a start.

In informal tests, C|Net reported:

For most native applications that don't depend on a cellular or Wi-Fi connection, the iPhone 3GS was consistently faster. For the photo gallery, camera, calculator, calendar, notes, clock, and contacts list, the iPhone 3G lagged about 2 seconds behind. No, that's not a huge difference, but it was a difference nonetheless. We noticed a similar change when using the Spotlight feature and opening the Settings menu.

We saw a bigger change in other areas. The iPhone 3GS opened the iPod player almost 5 seconds faster, and it was much quicker at loading some notoriously slow apps. For example, Bejewled 2, which can take up to 12 seconds to load on the iPhone 3G, started in just 5 seconds on the 3GS.

The superbly detailed AnandTech found that:

The new 3GS renders web pages 128% faster, on average, than the old iPhone 3G. The 45% clock speed boost alone isn't enough to generate such a large performance increase, this is a new microarchitecture. . . While the old iPhone 3G was no slouch, the 3GS is anywhere from 14 - 72% faster in basic application load times. It's the magic of a brand new CPU architecture.

For graphics in particular, the TapTapTap iPhone developer found that in OpenGL ES testing the iPhone 3GS is "generally close to four times faster than the 3G" and BareFeats crunched SunSpider Javascript benchmarks you may wish to review as well.

Real-World Usage

Percentages and benchmarks are useful, but nothing beats a side-by-side video for presenting real-world performance in actual use. The following clip -- a complement to an in-depth review from the always objective iLounge -- shows the iPhone 3G on the left and the iPhone 3GS on the right:

Ultimately, the iPhone 3GS is noticeably faster in day-to-day use and substantially faster for graphics-intensive applications (like games). Twice as fast definitely is a reasonable estimate.