You may have noticed that in a lot of the device reviews I’ve posted recently the performance section has been roughly the same, and there is a reason for that. The Snapdragon 615 CPU.
It’s no secret that SoC vendors have reference devices, which is the ideal specification device for a certain chipset. That could be a 720p screen, 1 or 2GB of RAM, 16GB of storage and an 8mp/2mp camera combo. There is nothing wrong with reference platforms. Well, there is nothing wrong with reference platforms, if the chipset is good, and that is where this editorial/rant comes in.
A large portion of the upper midrange phones I’ve reviewed this past year follow a certain trend. They’re between 5″ and 5.5” screens with 1080p resolution, they have 2 or 3GB of RAM and 16 or 32GB of internal storage. Lastly, they have the Snapdragon 615 System on a Chip from Qualcomm. The Snapdragon 615 is an octa-core SoC, which means it has 8 physical CPU cores, in 2 quad-core clusters running at differing frequencies. These are roughly 1.1Ghz and 1.7Ghz. It also has a GPU that is the Adreno 405 at 550Mhz and it’s built on the old and (ironically named) 28nm LP (LP stands for Low Power) process node from TSMC.
Now you have a rough rundown of what makes the Snapdragon 615 tick, I can get onto why I try to avoid devices with them. First off, 8x low-ish power CPU cores aren’t an ideal configuration. I get that Android can be relatively good with multi-threading processes, but a large majority of things you do will be better suited for fewer but higher performance cores. Qualcomm has tried to offset this by having two separate clusters operating at differing frequencies but it doesn’t change the fact that instead of having 8xA53’s, 2xA35s and 2xA72’s would be better, or if it’s not going to be a highly powerful device, 2xA35’s and 2xA53s. If those numbers are confusing you, here is a chart from ARM with regards to power consumption and actual power.
Because this chart is relatively new we have a few more options. At first, when ARM showed their hand in the 64 Bit core race, they had the Cortex A57 and the Cortex A53, and we had no idea what these related to. We assumed that the A57 was the A15/A17 core because it was bigger and more power hungry, but we wrongly assumed (we being journalists) that the A53 was the 64Bit version of the Cortex A7, and that the higher performance just came at the cost of the higher power draw. We were wrong, and this updated core roadmap shows that.
In the 32Bit SoC wars, we didn’t see 8xA9’s, because it’d consume too much power, and the performance over the A7 for the increased power draw wasn’t worth it. But because of the way we were thrust into the 64 Bit core wars (remember, a Qualcomm Exec once said that 64Bit and high core counts were stupid), we had just come off of the 8xA7 SoCs and people, especially people in Asian countries, were used to seeing high core counts for a few months at this point, so new devices going to quads again? That wasn’t going to fly.
Whilst I’m really not a fan of the 8 Cortex A53 solution, it’s workable. My biggest problem with the Snapdragon 615 is the GPU and the process it is made on. We’ll start with the process. It’s old and inefficient despite it’s name standing for low power. There are countless better 28nm nodes, heck there are even experimental 22nm nodes (22nm FDX from GloFo) that give you the power draw of something like 14nm with the same switching speeds, but the cost of a 28nm node. Why Qualcomm decided to use a first generation 28nm node from TSMC is beyond me, it must have been very cheap.
Speaking of why they did something, I don’t understand why the Adreno 405 GPU was used either, or why they seem to want OEMs to pair a Snapdragon 615 with a 1080p screen. It just isn’t powerful enough to provide a consistently smooth performance at that resolution. Whether it be the Moto X Play, the Alcatel OneTouch Idol 3 5.5, the Wileyfox Storm or the Honor 5X or any one of the plentiful SD615 devices with 1080p screens, they all seem to have performance issues, and a lot of them seem to have the performance issues in the same places, meaning that it’s unlikely to be a software issue.
Pulling down the notification shade is usually jittery, when scrolling through homescreens fast the device slows, and the entire device goes to crap when the camera is being used in low light. This is an issue on all of these devices, and one that had been pacified when the X Play got it’s Marshmallow update, but It still didn’t fix some of the performance issues that particular device had. The worst part about all this is that most, if not all of the manufacturers I’ve mentioned also released cheaper phones, with 720p screens and Snapdragon 410s. I happen to have those devices as well, and they consistently outperform the Snapdragon 615 devices.
As I stated before, having a reference platform isn’t a bad thing, in the case of the Snapdragon 410, it’s worked out really quite well, but when the reference platform is iffy from the start, it’s hard to fix that later.