Thanks to both of you for your answers.
I have my motherboard specifications but the issue is that am not familiar with the those terms.
So I will get a set of 4 Rams but what will you suggest to buy, I mean 4/8/16 GB for four slots?
Regarding the size of the RAM (4/8/16 GB) it will depend on what you currently have and the money you are willing to spend.
Your MOBO has 4 x DDR4 DIMM sockets supporting up to 64 GB of system memory.
You can put 4 x 16 GB and with that you would be at the top supported by your MOBO.
Or you can put 2x16 GB and you would have 2 free slots for future memory expansion.
If you choose the latter I advise you to use the slots of the same color (2 black or 2 gray).
The recommended amount varies greatly depending on the use that is going to be given to the PC. A calculation server where perhaps 72GB is scarce is not the same as a gaming team where with 8GB we are served in the short term. The rule of thumb for RAM is as follows:
* Have a sufficient amount for all active programs to fit in main memory: The most important thing, because if our team is going to be constantly pulling paging, it doesn't matter if we have the fastest RAM in the world, we are going to have a huge neck of bottle bringing and carrying data to disk.
* Have dual/triple/quad channel enabled if our platform supports it: That is, 2 in 2, 3 in 3, or 4 in 4 modules respectively. This is one of the most important things, since having dual channel active means doubling the effective bandwidth when several memory pages are moved at once. Under ideal conditions, having two modules at 1333Mhz gives us as much theoretical bandwidth as a single module at 2666Mhz, of course for a fraction of the price.
* Have the highest possible frequencies in our modules.
* Have the lowest possible latencies in our modules.
Returning to the amount, the most demanding use will be video games, my opinion is that the perfect amount to be safe for several years is 16GB. In somewhat tighter budgets, mounting 8GB is a very adequate compromise to meet the minimum requirements of the vast majority of current and upcoming titles without making major concessions, except if we are more careful to close most applications, especially if we are one of the that we have Chrome open with many tabs. 4GB seems scarce even for some current games, and we should avoid it if possible.
For advanced users, who are going to render, edit images at high resolutions, or who usually have several large virtual machines open, the only limit is your pocket and the maximum memory supported by the platform (in your case 64 GB).
Sorry for the long explanation, but from what you said you are not familiar with the technical terms, so I tried to explain and give you examples as simply as I could.
