Dual Channel to Triple Channel?

[arkuatic]

Q: If I buy Kingston HyperX 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 and LATER buy another pair of the SAME memory would I get triple channel memory or is the memory meant for dual channel despite how many same set of memory i put in?
http://www.newegg.com/Product/Product.aspx?Item=N82E16820104155

 

[TheViper]

So long as the you have 3 sticks of the exact same* DDR3 memory and your motherboard supports it, you can run it triple channel.


* - Speed doesn't have to be the same depending on the motherboard but it will revert to the slowest speed for all 3 sticks.

 

[arkuatic]

I went to my local fry's store and asked an employee about the same exact memory above if it would be compatible with my i7 920, he replied, "no because the 1366 socket allows only triple channel and this memory is dual channel." So I asked, "well can't i just buy two set of the same memory and plug that in so I can triple channel?" His reply was "no because this is dual channel memory you need to buy the ones that say triple channel."

I'm a bit skeptical with his answer because he did look like he was improvising his answer but I really can't risk wasting time and money buying memory that will not work. I don't see the thought of having to purchase 'triple channel' labeled memory when its basically 3 sticks of ddr3 sdram 1333 instead of two. Am i wrong here or is there something my ignorance cannot perceive?

 

[TheViper]

There is a reason the clerks behind the counter are paid minimum wage and he just demonstrated why.

I wonder if that clerk ever wondered how those Core i7 dual channel vs triple channel benchmarks came out. Perhaps he's mistaking triple channel for DDR3?

Pardon my mocking of him but to answer your question, yes, you may run it in dual channel (2 sticks) just fine.

 

[ujaansona]

If I buy Kingston HyperX 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 and LATER buy another pair of the SAME memory would I get triple channel memory

You will get triple channel.

 

[arkuatic]

Unfortunately there was a sale on the memory for 70$ which I brought a friend along to help me buy the other set so I can run triple channel(limited 1 per customer) and since he provided me false information I missed out on a great deal and wasted my friend's time as well as mine.

Just to make sure its clear me buying two sets of any 240-pin ddr3 sdram xxxxmhz memory is fine for the i7 920 and ill have tri channel correct?

 

[TheViper]

3 sticks of the same RAM is all you need.

You should try telling the store manager that his employee gave you false information and ask that the sale you came into the store for be extended to you.

 

[ujaansona]

If you get three RAM having same timing, speed, memory size & from the same manufacturer; they will run triple channel.

 

[shortstuff_mt]

If you buy a 2x2GB kit now and get another 2x2GB kit later you'll end up with four sticks of RAM. You need RAM in sets of three for triple channel operation. That means you would have to buy three 2x2GB kits and you'd end up with a triple channel 12GB setup (6x2GB). You're better off buying a 3x2GB triple channel kit.

 

[shortstuff_mt]

duplicate post

 

[arkuatic]

You need ram in SETS? Where are you getting this? 'Set' of ram= 2 in this case so I don't see why I have to buy 6 sticks of ram for triple channel.

 

[shortstuff_mt]

You have to have either three or six sticks of RAM in order for RAM to run in triple channel. I know it's fun to make fun of the Fry's employee, but he seems to be correct in this case.

http://en.wikipedia.org/wiki/Triple-channel_architecture

"The architecture can only be used when all three, or a multiple of three, memory modules are identical in capacity and speed, and are placed in triple-channel slots. When two memory modules are installed, the architecture will operate in dual-channel mode."

 

[TheViper]

You don't need 6. Just 3.

I think Shortstuff_mt was simply pointing out if you bought 2 x 2 GB now and another 2 x 2 GB later that it would make more sense to either grab another 2 x 2 GB for 6 x 2 GB or just buy a single 2 GB stick later for 3 x 2 GB. Either way you get triple channel.

 

[TheViper]

Shortstuff_mt, the Fry's clerk is most certainly incorrect. He claimed that a 1366 based motherboard couldn't run dual channel.

 

[arkuatic]

So from what you're saying I wont get triple channel if I have 4 sticks?

*Also that same fry's employee said, "oh yea the i7 just came out recently." this after noon when i stopped by.

 

[TheViper]

Maybe he considers 1 year and 2 weeks ago as recently. *snickers*

Correct about the 4 sticks. Dual is sets of 2 and triple is sets of 3.

 

[shortstuff_mt]

So from what you're saying I wont get triple channel if I have 4 sticks?

BINGO!

 

[arkuatic]

http://www.tomshardware.com/forum/266444-30-triple-channel-dual-channel-performance

According to this post the 3 sticks would run triple while the 4th run single? Or am i reading it wrong.