Test Results: CPU Core Benchmarks
Basemark OS II Full (Anti-Detection)
Basemark OS II is an all-in-one tool designed for measuring overall performance of mobile devices. It scores each device in four main categories: System, Memory, Graphics and Web.
The System score reflects CPU and memory performance, specifically testing integer and floating-point math, along with single- and multi-core CPU image processing using a 2048x2048-pixel, 32-bit image.
Measuring the transfer rate of the internal NAND storage (Memory) is done by reading and writing files with a fixed size, files varying from 65KB to 16MB, and files in a fragmented memory scenario.
Calculating the Graphics score involves mixing 2D/3D graphics inside the same scene, applying several pixel shader effects, and displaying 100 particles with a single draw call to test GPU vertex operations. The benchmark is rendered at 1920x1080 off-screen 100 times before being displayed on-screen.
Finally, the Web score stresses the CPU by performing 3D transformations and object resizing with CSS, and also includes an HTML5 Canvas particle physics test.
Apple's Cyclone architecture performs well in CPU-centric benchmarks. A year after its initial launch, it's still faster than the latest Krait and ARM CPUs. Even Nvidia’s Tegra K1 couldn’t beat the A7 in these tests, the lone exception being Geekbench 3 Pro Multi-Core. Now with the A8 SoC, Apple looks to extend its lead even further.
The improved Cyclone cores in the A8 outperform the A7 in the iPhone 5s by 34% in the System test, which is significantly more than the ~8% bump in clock rate can explain. This is likely the summation of several smaller tweaks, like the improvement in sequential memory access, rather than a significant pipeline change.
The iPhone 6 sees only a modest improvement over the 5s in the Web test, which includes a particle physics simulation similar to 3DMark Ice Storm Unlimited, a test that Cyclone has never handled well. Still, the 6 Plus manages to score 40% higher than the Note 4.
The iPhone 6 Plus performs on par with the 5s and HTC One (M8) in the Memory metric, with the iPhone 6 showing a slight advantage. The iFixit teardown of the iPhone 6 shows it using SanDisk NAND, which, based on this measurement, seems to offer slightly better performance than the SK Hynix NAND found in the 6 Plus. The Note 4 offers the best storage performance of the group.
Looking more closely, however, shows the iPhone 6 averaging around 3x faster in read operations, while the Note 4 is about 2.5x faster in the variable length and fragmented write tests. Boosting the Note 4’s overall Memory score is its fixed size write throughput, which is 6x faster than the iPhone 6.
The PowerVR GX6450 in the A8 gives mixed results in the Graphics test. It's 73% faster than the 5s, topping Apple's claim of 50%-better GPU performance, but is still slower than the Adreno 330 and 43% slower than the newer Adreno 420. We've seen the PowerVR G6430 in the A7 perform better than the Adreno 330 in some benchmarks, so Imagination's latest GPU still has a chance to take the overall win.
Curiously, the 6 Plus outperforms the iPhone 6 in the Graphics test by 7%. This test is run off-screen so both phones should fare similarly. Is this just an anomaly or will we see the trend continue in our other graphics benchmarks?
Geekbench 3 Pro (Anti-Detection)
Primate Labs' Geekbench offers a wide selection of cross-platform compatibility, with apps available for Windows, OS X, Linux, iOS and Android. This simple system benchmark produces two sets of scores: single- and multi-threaded. For each, it runs a series of tests in three categories: Integer, Floating Point, and Memory. The individual results are used to calculate category scores, which, in turn, generate overall Geekbench scores.
Once again we see the improved Cyclone CPU extend its lead over Krait in single-core performance. The iPhone 6 is 54% faster than the Note 4 in the Integer test and 66% faster in Floating Point math.
Compared to the A7 in the iPhone 5s, A8 sees about a 15% average improvement for the Integer performance tests and 18% for the Floating Point tests. As noted earlier, cryptography sees the smallest improvement, while the Lua and Dijkstra tests improve by 30%. The BZip2 and JPEG compression tests, which should rely on sequential memory access, show around a 15% improvement, nearly the same result as the STREAM Copy memory test.
In the multi-core test, we see the Galaxy Note 4 leverage its quad-core Krait 450 CPU to outperform the iPhone 6. Even with half as many cores and almost half the clock rate, Apple's improved Cyclone CPU is within 10% of Krait 450.
The multi-core performance gains for the iPhone 6 relative to the 5s are similar to those in the single-core tests.