Early iPhone 3G S OpenGL Test Results
Holy crap, this thing is fast
The new iPhone 3G S arrived today and I’ve been putting it through its paces by testing it out with several different configurations of the latest build of Plasma, an application I am developing for Tap Tap Tap. Plasma utilizes a lot of particle animation and is CPU intensive, so I’ve been eager to get a build running on the 3G S as soon as possible. As a reference point, I also ran all of the same tests on a second generation iPod Touch.
Hardware comparison
iPod Touch 2g:
CPU: Arm 6 running at 533 MHz
GPU: PowerVR MBX Lite
iPhone 3G S:
CPU: Arm 7 running at 600 MHz
GPU: PowerVR SGX
Results
After several different tests, the overall trend was starkly apparent:
the iPhone 3G S ran about twice as fast as the 2g Touch in every test
The results are specific to our own application and are definitely not all-inclusive, but the figure is still significant and interesting. I haven’t updated any of the code to take advantage of the OpenGL ES 2.0 features, so this is simply comparing ES 1.1 performance on the two platforms.
The somewhat faster, next-generation CPU obviously should make a difference, but it looks like the PowerVR SGX has a very significant performance gain over the MBX.
(Update)
The question of the CPU contribution to performance was nagging at me, so I dug up the C source code for the Scimark2 benchmark suite from NIST and put together a quick test application for the iPhone. Scimark2 is a set of numerically intensive tests including FFTs, successive over relaxation (SOR), Monte Carlo calculations, matrix multiplications and LU decomposition - calculations similar to the ones we do in our application.
I ran the test on the Touch and the 3gs with both small and large (cache-blowing) datasets to see how they compared. Here are the results:
iPhone 3Gs: 6.42 Mflops (small dataset) 5.86 Mflops (large dataset)
2g Touch: 5.21 Mflops (small dataset) 4.86 Mflops (large dataset)
In these tests the 3G S comes out about 20% faster than the 2g Touch. Given that the clock speed of the 3G S is only about 12% faster, there is definitely some extra oomph coming from the upgraded processor architecture, but I think it’s pretty clear that the PowerVR SGX’s contribution to our performance increase is substantial.