Benchmark Variance: Not Every SoC Is Created Equal
We could go into a lengthy diatribe about how not every piece of technology is created equally, or how we shouldn't complain considering the price of the phone and the features being offered. We could talk about the way in which market demands mean that things don't get to be “fully baked” or completely realized until after the fact when the dust settles.
We could. But we won't.
Frankly, our particular Nexus 5 has a slower CPU core than most, and there's no getting around it. The benchmarks will reflect this, as anything solely determined by CPU, or mixed CPU/GPU performance suffers, while workloads that exclusively tax the GPU line up with other findings.
It was disappointing to see our unit consistently rate equal to or worse than either the HTC One or Samsung Galaxy S4 in AnTuTu (both Snapdragon 600-based devices). In fact, our Nexus 5 using the stock ROM and kernel never even reached the performance levels of any of its Snapdragon 800-equipped cousins, including the LG G2 with which it shares so much in common.
The performance deficit also shows up in games where physics and decent AI are being used at the same time as intensive graphics. Asphalt 8, for example, is laggy in certain intense sections, and the slow-down is particularly noticeable during collisions. This lag doesn't affect the gameplay, and it probably became more bothersome once we knew what was causing it.
So, we investigated solutions, first by using brute force. We flashed ROMs and kernels and saw sometimes marginal increases, sometimes dramatic performance jumps. Eventually, we had this Nexus 5 beating out the consistently highly-rated (and proven to cheat) Samsung Galaxy Note 3. Unfortunately, this was always at the cost to battery life and heat dissipation.
Sometime during this process we remembered a lesson long forgotten: KISS, or Keep It Simple, Stupid. So we did just that. We flashed back to stock, rooted the device, and then checked for PVS rating, which defines how slow or fast the CPU core is in terms of binning (something that had been revealed during the first few months of the Nexus 4). The SoC scored a whopping 1. That means that the internal Qualcomm QA test that is built right into the chipset rates our Nexus 5 as the slowest on a scale of 1 (slowest) to 5 (fastest).
We sighed, and accepted our fate. After all, this could very well be your experience if you purchase a Nexus 5. At the very least it answered some of our questions.
If you're already the owner of Nexus 5 and are interested to see how your handset's SoC stacks up, do the following on a rooted device:
- Grab a terminal emulator from Google Play
- Type “su” in terminal emulator
- OK the Super User request
- Type “dmesg | grep PVS”
Here's hoping you have better luck than us with your Nexus 5.