i7-4790k & i7-3820 Memory Bandwith Problem?

[Revenge96]

(Sorry for bad english) Hello there, so, i'm making a new Desktop PC with an i7-4790k...i compared it with my old CPU, the i7-3820...and i saw that there is a particular specification, the maximum memory bandwith:
i7-3820: 51,2 GB/s
i7-4790k: 25,6 GB/s
That made me think, and i was wondering, because i'm pretty ignorant to these arguments, is it related to the RAM? does make it a difference if i have only 16 GB of ram?

 

[ZENprime]

In short : you would not see extra performance except if you have 4 x 4 GB ram sticks , do not upgrade into 4790 if you still have 3820 working ; you will not see any noticeable performance increase . however you get lower heat and temperature output , which is not worth buying 4790 over 3820

In details :
it is because of the memory channels in the processor 3820 has a quad channel and 4790 has dual channel
quad channel has higher speed than the dual channel for the same memory size but require more memory sticks

Motherboard generally have :
Dual channel ram slots
A1 colored black for example
A2 colored red for example
B1 colored black for example
B2 colored red for example

If you have 2 x 4 GB ram and you want to use dual channel ; you will install the first stick in A1 slot which is black , and the other stick in B1 which is colored black too , they come in same color to make it easy to install dual channel for you
Generally motherboard design ram slots :
On quad channel processors :
A1 red
A2 black
B1 red
B2 black
on the left of the processor
--------------------------------
c2 red
c1 black
d2 red
d1 black
on the right of the processor

to install quad channel memory you need to install dual channels on each size (put a ram stick in each black on a side and each red on the other side )
mean that you need at least 4 ram sticks to use quad channel

 

[Revenge96]

Lets say that i already bought everything, and i have 2 x 8 GB ram with a dual channel motherboard...i should put those 2 stick in: A1 the first one, and B1 the second one?

 

[RobCrezz]

basically the change to the 4790k wasnt much of an upgrade for you, because the 3820 was based on the higher end x79 platform which takes "Quad channel" ram, almost doubling the bandwidth (also 6 core i7 cpus were available on x79.

 

[ZENprime]

Lets say that i already bought everything, and i have 2 x 8 GB ram with a dual channel motherboard...i should put those 2 stick in: A1 the first one, and B1 the second one?

you will see 2 colors in ram slots on motherboard
Put the two sticks in same color slots (black if available)

 

[Revenge96]

ok thx for the information, this problem is solved