Earlier quoted context omitted.
It's possible that there is no dual channel, so the laptop would not take a performance hit due to mismatched sticks. I can not tell the configuration of the slots from their specs page [0]. Their configuration page [1] confirms that it's 8GB+32GB to get the 40GB. Why wouldn't they just offer 2x16GB to get the dual-channel memory? Unless, of course, the laptop does not support dual-channel memory... -- [0]: https://s…
Most likely the motherboard has 8GB soldered on, they do that with a lot of laptops these days unfortunately.
but most people would like to upgrade, and if it is going to most likely work on the slower speed of the second stick, it defeats the performance point altogether.
just poor design in this case.