Do i5/i7 motherboards require RAM (memory) to be paired?

[sygyzy]

Sorry, I have been out of the loop for a while. Do the new core i5/i7 architectures/motherboards require (recommend?) RAM modules to be paired, or can I install say 3 sticks if I wanted?

 

[Moonzi]

Correct me if I'm wrong, but the recommendation would depend on the mother board I believe, there can be duo channel and tri channel mother boards for the RAM dimms to match up

 

[sygyzy]

Wow tri-channel? I never heard of this.

Edit: So I guess you're right - it's a function of the motherboard, not a specific chipset or anything. I downloaded the manual for a Gigabyte GA-P55A-UD4 and it explains you should install dual channels in Slots 1 & 3 then 2 & 4

 

[ekoostik]

Correct me if I'm wrong, but the recommendation would depend on the mother board I believe, there can be duo channel and tri channel mother boards for the RAM dimms to match up

I was about to say you are wrong and correct you, but then I reread the original post. I understood the OP's use of "new" to mean the P55 chipset. But since that wasn't specified I'll just add some clarification:

The i7 9xx chips using the 1366 socket and X58 chipset are tri-channel.

The i5 and i7 8xx chips using the 1156 socket and P55 chipset are dual-channel.

Gigabyte confused things a litle by releasing an upper-end 1156 motherboard with 6 memory slots. (There may be others but this is the only one I'm aware of.) However, they support this with fancy engineering and what's often lost is the fact that two of the slots can only be populated with single-sided RAM. From an AT article (P55 Overclocking Showdown - ASUS, Gigabyte, and EVGA at the OC Corral (Page 6 Updated)):

We’re a tad bemused at the presence of 6 DIMM slots on a P55 motherboard when the processors are dual channel only when run without buffered DIMMS. Oddly enough, the extra slots are for running single sided modules in dual channel interleaved mode over 6 slots.

 

[Ayah]

They don't need to be paired. Though, if you don't buy paired sets, you don't have a guarantee that your sticks of memory will like each other and run.

You also don't need 3 sticks of ram for an X58. You get the best performance with sticks in multiples of 3, but it's not required. You can run 1 stick, or 2 sticks, 4 sticks, 5 sticks if you wanted. You'll lose the benefit of having a triple-channel memory controller though.

Same with the dual channel memory controller on the LGA1156 platform. You can run 1 stick or 3 sticks if you wanted. It'll still run, but you don't get the full performance of your memory controller and memory.