Soldered RAM in macbook air 2015 This question is just to fulfil my curiosity about how my mac works.

I have a macbook air (2015) with 8GB of soldered RAM.
And for what I know 2 RAM modules of 4GB are faster than 1 module of 8GB because they work in parallel and each has it's own bus, but as it is soldered there are no modules, so, are they more like 2x4GB, 1x8GB, 4x2GB, ...?
From the images at iFixit.com, you can see that the RAM, soldered directly onto the MBA logic board (4GB of RAM in orange outline,) is not soldered onto a RAM carrier as you would find in a computer with removable RAM. I have no absolute proof, without diving into arcane documentation, but I'm sure Apple has designed the RAM to be interleaved if that is the technology they are using.