Dual channel (ram)

[TAPION]

Can someone tell me what dual channel means? If my motherboard supported dual channel and I stick a single 512mb 3200 piece of ram in and then I were to stick 2x256mb 3200 ram in. What will the difference in performance be?

[Play_The_0dds]

ok, dual channel ram means there are two ram pipelines to the cpu to try and help the bottleneck caused by the system bus. on all the dual channel boards i have seen if you have one stick of ram it runs in single channel mode. to get dual channel to work you have to have a matched pair of what ever ram you intend to use, like if you bought 2 sticks of 256 or 512, make sure they are the same brand and spec. install both in the same color slot, like if you put one in the blue slot, put the other in the blue slot. this will make the dual channel activate. if you mix it(one black, the other blue), it will still run just not in dual channel mode. if you decide to add more ram you will need another identical pair of ram to go in the two open slots, if you only add one more, it will see the ram but your back to single channel mode. it is very important to have the exact same chip in both slots of the same color.

[TAPION]

So what is the advantage of have 2 of the same ram on a motherboard that supports dual channel ram?

[Play_The_0dds]

the advantage is:
with two identical sticks of ram the motherboard activates dual channel , if they are not identical the system can not adjust for voltage and other differences that are caused by ram of different specs.
lets say you have 2 kingston 512 pc3200ddr. you put both on the blue slots. you have dual channel. if you are going to add more, you will have to add another matched pair(does not have to be the same as the ones on the blue strip) to the black. if you add one strip to a black slot you will detect and use the ram in single channel mode.
what the big deal is with dual channel is you have two pipelines to the processor from the ram instead of one.
the white paper explains this better then i can.
http://www.kingston.com/newtech/MKF_...Whitepaper.pdf

[TAPION]

so the RAM is used more efficently?

[curtybob]

yeah, just to elaborate, RAM tranfsers data in "strobes". Just like a strobe light, it cycles on and off. Well, what dual channel does is offset each pipe so that one stick is strobing on, while the other is off. It is really more complicated than that, but I thought short and to the point was the way to go. hope this helps.

[Overclocked Doc]

"Dual channeling" is definately something to shoot for if at all possible! The perfance gain is quite remarkable. Here's an example of one of my machines.

P4 1.8 northwood 1GB DDR (2 X 512)..@ stock (same channel)

Read = 1970mbs Write = 857mbs

1Gb DDR (2 X 512)..@ stock (dual channel)

Read = 2535mbs Write = 1015mbs

P4 1.8 overclocked @ 2.3 (no volt change) (same channel)

Read = 2517mbs Write = 975

P4 1.8 overclocked @ 2.30(no volt change) (dual ch.)

Read = 3200mbs Write = 1550

Note the difference between the stock numbers (dual channeled)
and the overclocked numbers (2.3) using single channel. Even with a 500MB. overclock the dual channeled set up shows a slightly better performance with 0 overclock.

These are "benchmark" numbers obtained running Aida Tool and are just a guide. I'm not suggesting you "overclock" your system ( can be a lot of fun though!) but definately look at "dual channeling your system. If it's got it then by all means "unleash it".

[TAPION]

Do you know if laptops can be fitted with dual ram? Or do any laptops even support dual ram?

[drums4life]

What about m/b's that have 3 mem slots? I'm running an Asus A7N8X-E Deluxe in my machine & it has 3 slots. I'm currently running 2 Kingston 512mb 3200 sticks in dual channel mode. But what if I add another identical stick into the 3rd slot? Will it convert my pc to single channel mode, even tho the stick is the same as the others? And if so, then what would be the real benefit of having or running 3 slots?

~drums4life~

[Overclocked Doc]

I'm quite certain that running 3 sticks will negate the dual channel aspect. Your read and writes will be dramatically reduced. It is possible that running the third stick will help your partiuclar situation, depending on what programs you run. Personally I would stick with the dual channel.
If you had a board with 4 Dimm slots then filling all would still support D/C.

[sirchumpalot]

Originally Posted by Overclocked Doc

I'm quite certain that running 3 sticks will negate the dual channel aspect. Your read and writes will be dramatically reduced. It is possible that running the third stick will help your partiuclar situation, depending on what programs you run. Personally I would stick with the dual channel.
If you had a board with 4 Dimm slots then filling all would still support D/C.

I own the A7N8X-E Deluxe mobo, and im referring to the users manual right now. If you use all three slots, Dual Channel is still supported. Use A1(blue) and B1(blue) slots for dual channel, A2(black) and B1(blue) or use all three slots. According to this, it says that it is still dual channel compatable.

[Cenrith]

My mother bord has 2 seperate dual channel slots, im currently running my pc with just one stick in one of the four slots. i just bought a dual kit, will i have to unplug the single stick or will it be fine as long as i plug the dual kit in the same coloured slots?

[Overclocked Doc]

Generally speaking, if you use the same colored slots then both sticks will be on the "same channel" and not "dual channeled. Usually you will need to have one stick in each color to obtain "dual channel".

I would "Google" search your exact board if possible and check the mfg. specs to be sure.

I am using the words "usually" & "generally" because, as pointed out to me in the previous thread, things are not always the same "across the board".
I am still puzzeled by how the board mfg. achieves "dual channel" by using all three slots. Dual channel is based on "multiples of two" and also relies heavily on Ram that is "matched". I am really not sure how one can achieve that when there are 3 sticks. Having said that, it would appear that it is possible according to the board specs in question.

[sirchumpalot]

Yeah, it ultimatly depends on the mobo make and the mobo type.

On my A7N8X-E Deluxe, which i am running right now, im using both blue slots and it actiavted dual channel.

Works for me, but yes, refer to the above post for further information on your mobo make and whether you can activate dual channel

[ivan_g]

Can I use dual channel too? My m/b has 3 memory slots (one blue and two black), and I have 3 memories, one 512mb and two 256mb. Now they are set 512 on blue, and other 256 on black. My m/b is ASUS K8V-X.