HTC Sensation vs. Galaxy S II vs. Optimus 2X: Head to head

Synthetic benchmarks and Flash performance

Out of the three dual-core droids we're testing, no two use the same combination of CPU core, graphics accelerator and RAM. This should make performance testing and benchmarking fun.

Both the LG Optimus 2X and the Samsung Galaxy S II use dual Cortex-A9 cores but the 2X has them running at 1GHz, while the S II is clocked at 1.2GHz. The Sensation uses two of the good old Scorpion cores (based on Cortex-A8 but with heavy modifications from Qualcomm) running at 1.2GHz.

The graphics: Adreno 220 for the Sensation, Mali-400MP for the Galaxy S II, and an ULP GeForce for the Optimus 2X. As for RAM, the 2X has 512MB, the Sensation has 768MB and the S II packs a full 1GB of RAM.

So much for the horsepower, now for the track. We have the CPU-heavy BenchmarkPi and Linpack, the GPU-intensive NenaMark 2, the more general Quadrant and a couple of browser benchmarks - SunSpider (pure JavaScript) and BrowserMark (JavaScript + general browser performance).

This is the first time we're using NenaMark 2 - it is an OpenGL 2.0 ES test, heavy on the geometry, with high-res texture and a lot of shader effects (bump mapping, etc.). It was really taxing fro the mobile GPUs and kept the phones well under the 60fps mark. That served our purpose as the Samsung Galaxy S II is artificially capped at a framerate of 60fps so lighter benchmarks give false results, plus LCD screens usually refresh at 60fps so faster framerates don’t actually improve anything.

The Sensation limped a little on the single-threaded BenchmarkPi, falling behind the slower clocked Optimus 2X but it made up in the multithreaded Linpack, practically matching the Galaxy S II.

Quadrant crowned the Galaxy S II as the winner by a wide margin, while the Optimus 2X and the Sensation were nearly matched.

The NenaMark 2 graphics benchmark put the Galaxy S II ahead with the Sensation and Optimus 2X posting almost equal framerates. However, the qHD screen of the Sensation means that its GPU has to push nearly 35% more pixels than the other two. This puts the Sensation in second place, slightly ahead of the GeForce-powered Optimus 2X. Note: results are in FPS.

As for the two browser benchmarks, they really show the level of software optimization more than the raw processing power. The Sensation lagged behind in both benchmarks by a pretty wide margin - more than we can account for with the different CPU architectures so we’re not ruling out a bug or a system incompatibility here.

Still, both the S II and the Sensation ran Android 2.3.3, while the 2X was still on the less-optimized 2.2 Froyo. The conclusion to draw from this is that maker customizations can make a big difference.

Flash performance is an integral part of the browser performance, regardless of what some might say. There's no Flash benchmark (at least nothing up-to-date with mobile browsers) so we looked at real-life performance: YouTube videos and Flash games.

The Samsung Galaxy S II played YouTube videos up to 1080p and played the Flash games we tried trouble-free. The HTC Sensation comes in second. Its custom Flash player reached 720p (but choked on 1080p) and ran games perfectly too. The LG Optimus 2X however maxed out at 480p videos and, while most games ran without a hitch, we found some that lagged.

The HTC Sensation can offer some of the best performance around, provided that the apps are properly optimized for dual-core CPUs. Lack of optimization can be a stumbling block however, web browsing being the most noticeable area. On the plus side, the Sensation should have enough juice to play the latest 3D games for some time to come.