[SOLVED] why 8gb 4x2 ram better than 8gb 8x1 ram.

Solution
Modern CPUs are capable to do data transfer between CPU and RAM twice faster if two modules are used (Dual Channel mode). It is why two same RAM modules will work almost twice faster than single module with twice larger capacity. Server CPUs like Xeon and Threadripper may support quad channel mode which mean simultaneous data transfer from 4 RAM modules and accordingly 4 times faster transfer speed against single RAM module. A decade ago some CPUs had fastest RAM data transfer speed with 3 same RAM modules (Triple-channel architecture).

There is a catch related to RAM chip layout in module. There are Single Density (SD) modules and Double Density (DD) modules. Usually SD modules have RAM chips at one side and DD modules - at...

iPeekYou

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Just want to know why 8gb 4x2 ram better than 8gb 8x1 ram.

In practical analogy, think of the 8GB x1 as one giant warehouse with one door. You can only move so much stuff in and out of that door, even though the warehouse itself is big.

On the other hand, the 4GBx2 configuration takes that warehouse and gives it two doors. Now you can move stuff (theoretically) twice as fast, and with no loss in capacity.
 
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Colif

Win 11 Master
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Are you saying.
4x2GB ram sticks and 8x1GB ram sticks.
or
2x4GB ram sticks and 1x8GB ram stick.
Just want to know why 8gb 4x2 ram better than 8gb 8x1 ram.

I can see the confusion. I assumed it was 4 x 2gb sticks vs 1 x 8gb, but I can see why you asked. It could be any of them.

it doesn't matter as more sticks is still better than 1

I think finding a board with 8 slots might be a struggle. I know they exist now but how many boards were around when 1gb sticks were a major force? Besides server boards?
 
Modern CPUs are capable to do data transfer between CPU and RAM twice faster if two modules are used (Dual Channel mode). It is why two same RAM modules will work almost twice faster than single module with twice larger capacity. Server CPUs like Xeon and Threadripper may support quad channel mode which mean simultaneous data transfer from 4 RAM modules and accordingly 4 times faster transfer speed against single RAM module. A decade ago some CPUs had fastest RAM data transfer speed with 3 same RAM modules (Triple-channel architecture).

There is a catch related to RAM chip layout in module. There are Single Density (SD) modules and Double Density (DD) modules. Usually SD modules have RAM chips at one side and DD modules - at both sides. But this is not always true. What is worth to know - in DD modules CPU can't read data written in both "sides" in one go. It must read part from first "side" and then switch to second "side" which introduce some latency. Because of that SD modules are faster and this is mentioned also on motherboard manuals.
 
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Solution

Herr B

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May 29, 2020
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By going from 1x 8GB to 2x 4GB, you increase the number of channels from 1 to 2.
Which translates to a “larger funnel” that the information can flow through.
This will become significantly important when dealing with large chunks of information.

correct. However, important note:

4x2GB will actually slow you down again compared to 2x4Gb because then 2 ram slots have to be run per single channel.
 
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Endre

Reputable
correct. However, important note:

4x2GB will actually slow you down again compared to 2x4Gb because then 2 ram slots have to be run per single channel.

Well, that depends on your motherboard’s memory configuration.

OPTION 1:
Daisy Chain memory configuration leads to higher latencies by having 2 DIMMs per channel.

OPTION 2:
T-Topology memory configuration. You don’t lose anything by having 2 modules per channel because the distance from the DIMM to the CPU is identical for all 4 DIMMs.

Also, by having 2 DIMMs per channel, you gain Dual-Ranking (or even Quad-Ranking) which also increases memory speed a little bit by having 2 (or 4) different memory banks that can be accessed separately.