One of the interesting demonstrations for the recently announced Snapdragon 855 SoC here at Qualcomms Tech Summit was to do with power. In a dedicated area, Qualcomm had set up two pairs of devices, with Snapdragon 855 and 845 chips inside, and had images of power on two large screens designed to show the generation gain of the new chip promised more performance at a smaller processing hub .
For power consumption, Qualcomm had connected a few meters to the battery connected to each device. This gives the total system power, not just the power of the chipset, so it includes the screen, the connection, and anything else that can draw a microjoule or two.
On the first few units, Qualcomm went through a script of random online search. The script was allowed for automation, and a set of well-known web pages was continuously uploaded without cache. This is a fairly easy test, but it emphasizes the radio a good bit, as well as a changing display that has a lot of white area.
Overall, the S845 system used an average power of 2219mW, while the new S855 system was 1778mW. In the big order of things, this is 20% less power.
For the second demo, Qualcomm went to play. At the start of PUBG, we were told that the two devices were resolved in a 40 FPS mode with identical quality settings. This was also a scripted test, with the player who jumped out of the plane on the ground and quit. Obviously this requires some radio to connect to the online server and there would be a little disjoint between the two games based on server latency.
The values for these tests put the S845 to an average power of 3276 mW, and the new S855 at 2543 mW. The difference in this test would be 22%.
All this is good and good, although a big warning came up: none of the screens were brightness calibrated. The Qualcomm representative said the brightness of the devices was "eyeballed" to be in the same region, but based on personal experience, it's never a guarantee and they can be as much as 20-30%. The panels were also not from the same manufacturer, so there are also questions about panel efficiency.
All is said, this may not be unexpected (or it is unexpected to show power at this point unexpectedly). There must be some confusion as Qualcomm has to meet expectations, but the final tuning must also take place. In addition, it will be up to Qualcomm's OEM partners to put SoC into an environment that may or may not be effective for radio, screen, thermals, etc.
We wait until we take some hands with the hardware until we take some reviews. Funnily, I have my screen calibration tool with me. To be fair, Qualcomm said that they would allow me to equate the screen's brightness to both, which was a nice gesture, but we did not notice the workloads they used and there was no chance I was allowed to run our power tests on this time. Stay tuned, as power economy will be an interesting story here.