I agree with the other posts here. It really depends a lot on what you are trying to accomplish. A lot of it depends on the operating system that you are running too. If you are only running a 32 bit operating system you are not going to be able to use much more than 6 GB or something like that. That isn't as common these days, but there are still some computers out there that are shipping with a 32 bit OS to keep the cost down.
I read an article a little bit ago that basically said unless you are doing some super heavy duty processing or high end gaming, there is a point of diminishing returns above 16GB for most desktop PC's. If you are getting a really great deal on the RAM, you can throw in the 64 GB but otherwise I would probably stick to 32GB or less. Looking at the other answers it appears that is kind of the consensus.
I have some old Core 2 Duo computers sitting on a shelf in my office. They all have 4 GB of RAM in them. I can put an SSD in them and Windows 10 64 Bit and they practically scream. For general every day web surfing and word processing they are fantastic.
To me, sixty four GB of ram is a waste of resources. I do no longer assume you NEED it. You actually need to be searching intently at how lots assets you're using on your system firstly and then pass the test from there.
Sixteen, 24, 32 gigs of ram are usually to be had and they serve at there peak. You can usually take your choice but 64 is a piece tons. Your CPU will possibly hit its restricted first earlier than it requires you get a bigger ram. So I'd advise if a 32 gig ram Is obtained at highest. So if the case can be your CPU calls for a bigger ram (which probably it may not) then you could move to acquire it.
It really depends on what you want to achieve. But most cases a combination with RAM and SSD hard drive can give you better results
Maybe you could set up a lot of RAM disks, like imdisk for example
If you love to run a lot of software that needs much RAM to cache data, then more ram is very useful. If you're upgrading from like 2 - 8 GB, you might not need more than 16 to 32 GB of Ram for your PC. Keep in mind that you need to have the right operating system to actually use it (64 bit).