Differences between LGA1156 and LGA1366?

[B@nj0 P3do]

What is the Differences between the two CPU sockets(LGA1156 & LGA1366) Other than the price?

I searched on google and found out a bit badly written information, but what I could gather is that;

the GPU controller is on the CPU on LGA1156 and on the north bridge* on LGA1366.
2 channel Ram controller on LGA1156 and 3 channel Ram controller on LGA1366**
2/3 GPU SLI/CrossfireX support on LGA1156 but only at 8x/8x
4+ GPU SLI/CrossfireX support on LGA1366 16x/16x

Is there any more differences?

*: Where is this?
**: What is the difference between 2 channel and 3 channel ram control?

[vesseblah]

the GPU controller is on the CPU on LGA1156 and on the north bridge* on LGA1366.
2 channel Ram controller on LGA1156 and 3 channel Ram controller on LGA1366**

*: Where is this?
**: What is the difference between 2 channel and 3 channel ram control?

Chipset on the motherboard is basically two large highly integrated custom chips called Northbridge and Southbride. The naming comes from the block diagrams that usually look like this.

The so-called Northbridge is the chip higher (North) in the picture, nothing more magical to the name. P55 and X58 in the motherboards are the model numbers of the chipsets.

In traditional chipsets Southbridge further away from the CPU behind slower data bus connected to Northbridge includes slow I/O like ISA cards, soundchip, harddiscs, USB, serial ports, LAN and so on. Northbridge which is connected directly to CPU with fast bus handles fast I/O which has traditonally been graphics card (AGP/full-rate PCI-E) and memory. In motherboards with integrated graphics processor, the GPU is also located in Northbridge. Without exceptions Northbridge has a heatsink and sometimes fan, but Southbridge doesn't necessarily need one even though most motherboards has a heatsink on it too.

LGA1156 chipset and board uses this traditional setup, while LGA1366 chipset has moved part of the Northbridge functions (RAM controller) directly into CPU for faster RAM access, but Northbridge still handles PCI-Express connectors.


2 channel vs 3 channel RAM should be fairly self-evident. In 2-channel setup you add RAM sticks in pairs, like for example 2 x 2GB, and in 3-channel (triplechannel) you add RAM sticks in sets of three, for example 3 x 3GB. 3-channel setup is in theory slightly faster, but it does not really show in any practical applications.

[B@nj0 P3do]

2 channel vs 3 channel RAM should be fairly self-evident. In 2-channel setup you add RAM sticks in pairs, like for example 2 x 2GB, and in 3-channel (triplechannel) you add RAM sticks in sets of three, for example 3 x 3GB. 3-channel setup is in theory slightly faster, but it does not really show in any practical applications.

Like this?


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But there are LGA1156 Motherboards with more than 4 memory slots, what if you put 3 memory sticks like the 3 channel image, how would this perform?

(Asking since I really like learning new stuff about computers )

[vesseblah]

Ok, this is really quick and dirty diagram, but should illustrate point.

Usually 2-channel motherboard has 4 RAM slots marked with 2 different colors like on your picture. You put 2 RAM sticks into the sockets marked with same color, like this for example

12 34
*  *

If the motherboard has, let's say 8 slots for RAM, those are still in marked pairs, and would be filled something like:

12 34 56 78
*# *# "+ "+

In 3-channel board that has 6 RAM slots, you'd fill it something like this:

12 34 56
*  *  *

Important thing is that all pairs/trios need to be identical RAM sticks, but if you have two pairs of sticks, the pairs can be different types of RAM but the computer will use the specs of the worse pair for all four sticks.

Motherboard's manual will have real pictures of where you need to put the RAM sticks and there is very little room for confusion.