How much RAM you need in a system depends on what you intend to do with it, how long you intend to keep it, and whether or not you can upgrade your memory post-purchase. This last point is important, as many high-end laptops have eliminated user-upgradeable RAM in order to reduce system thickness by roughly six nanometers.
LOL - ummm, no. I think you might be confused there.
1 nanometer (nm) = 1 billionth of 1 meter.
1 nm = 1 millionth of 1 millemeter or 0.000001 millemeter!
There are 25,400,000 nanometers in 1 inch!
A human hair is about 75,000 nm thick!
The smallest distance the human eye can distinguish is about 0.1 millimeter or 100,000 nm! So 6nm is nothing and would take a powerful microscope to see.
The amount of RAM one needs has nothing to do with how long a user intends to keep a computer. Instead, it has everything to do with the tasks the computer will need to perform, and to a lessor but still important extent, the performance of the system the user is seeking.
Of course, while we may think we know what our computer needs will be 3 - 4 years from now, things change - and so may our RAM needs. Something to consider when buying or building a new computer.
GoMummy-GM is absolutely correct that, due to user demand, notebook makers are producing thinner and lighter notebooks today. That thinness is accomplished with surface mount technologies where the RAM modules are soldered directly onto the motherboards instead of using a socket - which adds weight and thickness. But sadly, it also prevents RAM upgrades.
There may be some misconceptions about power consumption too. Surprisingly, power consumption is much more a factor of the number of RAM modules (or sticks) rather than how big they are.
For example, there is no significant difference in power consumption between two 8GB RAM sticks and two 16GB RAM sticks. However, 4 sticks will consume significantly more than 2 sticks.
Also, the RAM technology plays a role there too. DDR4, for example, is more efficient than DDR3. But of course, we are limited to the type (and amount) of RAM the motherboard supports by the chipset, CPUs and design of the motherboard itself.
The amount of RAM also plays little role on power consumption caused by the page file. This is for several reasons.
First, Windows will use the page file regardless how much RAM you have installed. And that's a very good
thing! The difference is, with gobs of RAM Windows can stuff more higher priority
data in faster RAM instead of the slower page file. But it will still use the PF to stuff lower priority data. All that is good and why, even with lots of RAM installed, it is best to keep the PF enabled - and to just let Windows manage the Page File
(but that's for another discussion).
Second, hard drive motors are spinning and consuming power all the time anyway. They don't spin faster or more when accessing data. Yes, the stepper motor uses power when moving the R/W head about, but that is a very small amount compared to the constant spinning of the platters at 5,400 or 7,200 RPM.
With SSDs, they are consuming power just by being powered up. And accessing data does not add a lot more.
So regardless, GoMummy-GM is correct when saying adding more RAM (even if that means adding more sticks) rarely increases power requirements to any significant degree. While factory made computers (notebooks or PCs) typically come with power supplies that are barely adequate to support the hardware they come with, they can typically support more RAM. Upgrading the graphics or CPU, however, often requires a bigger power supply, but that's also for a another discussion.
I will add this. When buying or building a new computer, I always recommend buying more RAM than you think you will ever need at the time of the original purchase.
With surface mount technologies, this may mean buying a different model. But with socketed RAM the reason may not be as apparent. The problem is finding compatible RAM 3 or 4 years down that road. It is not always easy - especially when new RAM technologies take over as the current standard and factories retool for that newer standard.
So while 8GB is "good enough" for most users, I generally recommend at least 16GB and if the budget allows, just go for 32GB. As GoMummy-GM noted, having too much is better than not enough.