What is the difference between DDR3 and DDR4 and their speed?

[Bootahdah]

So I am planing to build a gaming PC, other parts are very good. The only thing I am confusing about is the RAM. I know that there are 2 types of RAM: DDR3 and DDR4. The mhz thing makes me confuse. Please explain and give me some advice of choosing RAM. 

[kelvinhall05]

If you are building a modern PC you should not be using DDR3.

[pumas]

ddr3 has slower frequencies and its just older.

[Kc7vwc]

DDR 4 is faster. Everything from 6th gen & later Intel uses it.

All Ryzen CPUs use it.

 

There's no reason to use anything needing DDR 3 with a new build. All the CPUs that would support it are 5-10 years old. 

 

As for the clocks on it, higher is faster. But check your motherboard specs to see what it supports. Generally 2600 - 3200 MHz should work on Intel or AMD without much trouble right out of the box. 

[Lenovo1984]

If you are building a new system you will be using DDR4. 

10 minutes ago, Bootahdah said:

I know that there are 2 types of RAM: DDR3 and DDR4.

Not quite. There was also DDR and DDR2 before those, though they aren't relevant at all any more (other than DDR2, it still has uses), and there are plenty more other kinds.