Respected technology site Ars Technica recently got its hands on a smartphone known as the Blackphone. While the phone itself is interesting (it's aimed at those who really take privacy seriously), the thing worth talking about is that it is one of the few handsets to sport NVIDIA's (NVDA -3.87%) Tegra 4i integrated apps processor and LTE modem. Was NVIDIA's Tegra 4i competitive on performance? Let's look at the results.

CPU performance looks fantastic for a low-end phone chip
While Ars Technica looked at the Blackphone/Tegra 4i in the context of higher-end smartphones like the iPhone 5s and the HTC One (M8), it's important to keep in mind that this chip was intended for low-cost, low-end devices (though the Blackphone that it powers is a $629 device aimed at the high end). Therefore it comes as no surprise that its CPU performance (as measured by Geekbench and Kraken) isn't class-leading.

However, if you look at the results of, say, a low-end Qualcomm (QCOM -2.53%) Snapdragon 400 (which was really NVIDIA's target with the Tegra 4i), the applications processor performance is quite good. In fact, in the Geekbench numbers, the Tegra 4i scored 687 in single core and 2042 in multicore, putting it handily above the Snapdragon 400 in the Moto G, which scored 312 and 1100, respectively.

Graphics performance looks good
Diving further into the benchmarks, we see something a bit weird. The primary test used for graphics is called GFXBench 2.7. There are two versions of this test: on-screen and off-screen. The on-screen results tell you how fast (in frames per second) a game is rendering at the device's native resolution.

To get an apples-to-apples comparison, however, we need to normalize for display resolution so that all of the phones are rendering the same thing. This is what the off-screen test is for. In the benchmark results posted with the Ars Technica review, the Tegra 4i-based Blackphone with a 1280x720 display resolution won against the iPhone 5s and Galaxy S5 in the off-screen tests, but lost in the on-screen tests.

 

Geekbench 3 (single/multi)

GFXBench 2.7 T-Rex (off-screen)

GFXBench 2.7 T-Rex (on-screen)

GFXBench 2.7 Egypt (off-screen)

GFXBench 2.7 Egypt (on-screen)

Kraken 1.1 (lower is better)

NVIDIA Tegra 4i

687/2042

27.0

18.0

63.0

44.0

11651

Qualcomm Snapdragon 801

938/3044

17.0

28.0

55.0

55.0

6512

Apple A7

1407/2522

27.0

36.0

64.0

53.0

6238

Source: Ars Technica.

This doesn't make sense -- if the Tegra 4i could win the off-screen test, it should handily win in the on-screen test on a lower resolution display than the Samsung Galaxy S5. This leads me to believe that Ars simply swapped them. From these results, it seems that the Tegra 4i is a fair bit behind the Snapdragon 801 and Apple A7 when it comes to raw graphics performance. Remember, though, the Tegra 4i was intended for low-end phones, so it's impressive that it can even put up a decent showing against the higher-end chips.

Foolish takeaway
Although NVIDIA's Tegra 4i seemed to offer competitive performance relative to the Snapdragon 400 found in many of today's low-end phones, it still did not find too many design wins. We'll never know whether this was a cost structure problem, NVIDIA's inability to offer an in-house connectivity solution, or something else.