We’ve heard and read a lot about Apple going with two different manufacturers for the A9 chip in its iPhone 6s. Some models ship with a processor made by TSMC while others come with a Samsung-made component. While you’d expect that Apple would ensure both are built to offer comparable performance, it appears that may not be the case. It’s already been revealed by Chipworks that the Sammy model is 10% smaller, but if a couple of videos recently published are anything to go by, you might be better off with a TSMC model…

Well-known tech YouTubers, Austin Evans and Jonathan Morrison both uploaded videos showing how they tested the TSMC and Samsung models against each other and ended up with the same conclusion: You’ll get better battery life from the TSMC model.

Jonathan Morrison ran a number of tests with both phones starting at 100% to see which drained the fastest. After shooting 4K video for an extended period of time, exporting the resulting 10 minute video in iMovie and running a couple of benchmark tests, the TSMC model had 62% battery left. The model using Samsung’s chip finished with 55%.

While 7% difference may not seem like much, running those same tests again with the same results would leave you with 24% on one, and just 10% on the other. In real world use, that could mean the difference between having battery life left at the end of the day, and not having any.

Austin took a slightly different approach to battery testing, by running the Geekbench 3 battery test with both screens set to the same brightness to see how long it would take each phone to hit 50% battery. The TSMC model lasted a full 50 minutes longer than the Samsung model, it also ran at a much cooler temperature.

Geekbench is typically much heavier on the processor than normal use, so Austin also played the same 1-hour long video on both phones to see how they compared with real-world video streaming. Here, the difference was just 1%. The TSMC model used 14% battery, while the Samsung model used 15%.

After watching both videos, and seeing the tests used, I think it’s safe to say that — for the average consumer — it won’t matter too much which model you end up with. After all, you can’t know which chip is inside your iPhone until after you’ve bought it, and the typical real-world tests showed minimal difference. However, if you’re someone who likes to push your iPhone to the limits; recording 4K video or playing graphically intense games, you may want to hope you get the TSMC version, because when the chips are pushed hard, the Samsung one doesn’t cope as well.

If you want to find out which chip your device has, you can download a free app called Lirum on the App Store which can tell you (or this one is free).

UPDATE: Lirum have announced that they pulled the app from the App Store claiming “We are aware of some serious issues or our Apps with the latest iOS models (iPhone 6S and iPad Air 2).” Whether that means its chip-detection tool is faulty or not, is yet to be seen. The app will be redeveloped and re-released in a few months.