Why S4 Is More Powerful than Tegra 3 (Most of the Time)

February 29, 2012
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Dual core or quad core? Which should you pick? If the decision was that simple, I’m sure most people would just go with the quad core chip. But what if the dual core chip this time is more powerful than the quad core one? From what we’ve seen in the benchmarks so far, it seems that the S4 beats the quad core Tegra 3 in most situations, except in some browsing tests and graphics tests.

So how can this be?  A single core of the Krait chip is simply based on a more advanced and newer chip architecture, that allows it to be more powerful than the Cortex A9 core inside Tegra 3. Tegra 3 is almost at the end of its lifecycle (at least as high-end devices go), while Krait is just starting its own lifecycle. But this still doesn’t really explain why a dual core chip can beat a quad core one. After all, a Krait core is not twice as fast as a Cortex A9 core, at least not if they run at the same clock speed, and in this case they pretty much do (depending on the Tegra 3 version).

The reason is simple, and I’m sure many of you have figured this out by now. Most applications are not yet optimized for multiple cores, which means that at least 2 or 3 of Tegra 3’s cores will go unused, and only the first one, or the first 2 cores at most will be used for the vast majority of applications. Since only 2 cores are put to use in most situations, this puts Krait at an advantage over Tegra 3, because its cores are more advanced and more powerful.

But this is also why things get a bit more complicated when it comes to browsing and games, because in many cases the browser can take advantage of all the cores in the phone, and also many new games, especially those optimized for Tegra 3, take advantage of all its cores and allow them to have richer content.

Plus, I’m not convinced yet of the graphics tests for the Adreno 225. In some it wins over Tegra 3, in others it loses, but even in those where it wins, the difference is small, and the Adreno 225 is tested at a lower resolution than Tegra 3, which gives it an unfair advantage. Could this also be the reason why most S4 devices that were announced so far are only using a qHD resolution to make it run at least as well as Tegra 3? Again, things are pretty unclear for now, but given Adreno’s past, I wouldn’t bet on it beating Tegra 3’s GPU.

Qualcomm has also announced the S4 Pro with the Adreno 320 GPU (along with a quad core CPU), of which we don’t know all that much about, other than the fact that  it’s on a new architecture, possibly much improved, but won’t be available until this fall. Even if it has significant gains over the current Adreno 225, it will probably have to fight GPU’s like Mali T604 or even T658, and Tegra 3+’s GPU, so it makes no sense to pronounce on which is better right now.

What do you think? Will you take a quad core Cortex A9 device now over a dual core S4 a bit later, or will you even wait for something like a dual core Cortex A15 device?

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