I was quite puzzled about this too. I had the following open if I'm not wrong:
- About 8-9 tabs in safari
- 2 documents in Word
- 3 PDFs, 1 which was extra large
- One VLC player on another desktop, paused
- PyCharm with a small code, no active processing
I was actively switching between the programs when I noticed that it went into the orange region for a short time (about the same length as your screenshot). Didn't suffer a performance hit or anything but it did confuse me a little as well.
That brought out the paranoia in me, wondering if 8GB will not be enough few years down the road. Especially since 8GB has been the norm for such a long time and most laptops are starting at 8GB. Now I'm even more confused because both the arguments for 8GB and 16GB seem to make sense.
Right, the way to think of it is get what you need, and what you can afford. 8GB is more than ample for the majority of users which is why they sell it with 8GB of RAM. RAM does very little to benefit multitasking and having multiple apps open will not do much to it. The real difference is in single applications, RAM is always used up no matter how much you have, so if you upgrade to 16GB you'll likely find you're suddenly using 12GB of RAM. This is because the OS will allocate RAM to whatever is needed and whatever is currently open/active, the rest is used as a buffer for the system. So if you have 3 apps running, it'll give 80% of the RAM to the currently active one, the rest will be a buffer for the other 2. Then when you switch apps it can quickly take you to where you were thanks to this buffer. Anything else will be coded into the scratch disk which is a slower form of RAM for instances that don't require immediate access.
Basically, the OS is very intelligent at optimising its RAM, and will use up as much as it can to give you the smoothest experience. If you are seeing it creep into the orange for a moment it's fine, it can operate just fine in the orange, it's just the system seeing if you need a little more here before taking some from somewhere else. If it is being sustained in the orange then you are approaching the limit of your machine, assuming your work doesn't change then this is likely to go unchanged and is still fine. When it starts peaking into the red it's a similar situation, except you have now approached the limit, again still fine, but you should think about more RAM as software updates in the future could add a little and push it over the edge.
So right now if you have $1000 to spend on a computer and the 8GB model is $1000, then get that and be happy. If you have $2000 then by all means get the 16GB. You won't regret getting more RAM, but get it for the right reason, get it because you are going to keep the system for a long time and your workflow may increase to use more professional applications. But 16GB is a huge amount of RAM in a modern system and is there if you do a lot of RAM intensive applications, not surfing the internet or Office apps.
If/when you come to sell the machine the specs make little to no difference on the resale value and it's a fools errand to try to spec a machine now for later sale. There's no point spending extra money on something that you will never make use of as that money is going to depreciate alongside the rest of the machine. If you sell the 8GB model in 4 years time and it cost you say $1500, expect $800 at most. If you had the 16GB model and it cost you $1900, expect $900. Macs aren't exactly rare or precious computers and the resale of these machines is increasing now they are non-upgradable, so there's no point splashing out extra for something that you never use, which gets you $50 back in the end. You may as well put that $400 aside and put it towards getting a new one.
So in short. If you can afford it and it's not going to stress you to spend that little extra then by all means, get the best you can afford. Just know it's not going to make it more valuable and it's currently unlikely you are going to make use of it. Are there other things you need such as a monitor or dock? It could be better to buy these and get the setup you want rather than the machine you think you need.
Hope that helps. You'll get opinions all over the place here with most adamant that 16GB is actually a small amount, and so 8GB is a tiny amount. Then you'll get others who think the opposite. Truth is RAM is not the same as it was 10 years ago and a lot of people hold the mentality that having more RAM = faster system, when these days it's more like having a car that goes 120MPH and adding a little extra to make it go 150MPH, do you need that?
