Dual Channel on newer motherboards

[freshy98]

I need some explanation on something I haven't read about yet.

When the first Dual Channel motherboards came out they had three memory banks, of which two could be used for Dual Channel memory.
They were also marked by two memory slots having the same color.

With the newer motherboards I see four banks on which there are two colors.
Meaning, two blue colored slots and two black colored slots for example.

Does this mean with the newer motherboards we have two Dual Channel banks instead of only one?

I would like to know this since I plan on buying new parts H1 next year and thinking of getting 2GB RAM in totall. Now, this could be 2*1GB in Dual Channel or 4*512MB in 2*Dual Channel.

Please let me know so this is clear to me since I am wondering about this for some time now.

 

[assemblage]

You should get 2x1gb sticks. That way you can always get another 2x1gb sticks and fill up the rest of the slots.

 

[freshy98]

Keep in mind that the latency's of 1GB modules is higher. CL3 against CL2.5 for high max speed modules (PC3700/PC4200).
By the time I will need 4GB I will have new other parts anyways

2*1GB is a bit cheaper compared to 4*512MB, but 512MB are available in lower latency's and higher max speeds.

 

[freshy98]

You should get 2x1gb sticks. That way you can always get another 2x1gb sticks and fill up the rest of the slots.

assemblage, what in the name of Pete does your answer have to do with my question?

 

[-=Mr_B=-]

Mate, "early" mobos your describing sounds alot like AMD /XP, the 4 or more slots equiped, are more then able to use all slots in a dual channel configuration, as long as you start with the marked slots, and build up evenly.

Best of luck.
B!

 

[assemblage]

I think your choices are 1,2,4 sticks. I still say go for the 4gig!

 

[-=Mr_B=-]

Depending on the motherboard, mine has 6 memory slots, still only supports 4 banks / channel tho.

Altho, im on a Gigabyte/Intel. Most other motherboards only has 4 slots
B!

 

[freshy98]

Mate, "early" mobos your describing sounds alot like AMD /XP, the 4 or more slots equiped, are more then able to use all slots in a dual channel configuration, as long as you start with the marked slots, and build up evenly.

Best of luck.
B!

The "early" motherboard with DC were three memory slot boards. Not four.
Not the NForce2 boards anyway.

 

[freshy98]

I think your choices are 1,2,4 sticks. I still say go for the 4gig!

What is your problem? I wasn't asking about how much memory I should take. That is up to me.
Only thing I asked was if modern/new motherboard with four memory slots have dual Dual Channel.
That is all!

 

[Biggles 266]

Dual channel is two memory controllers on board. Dual dual channel would be four memory controllers. So no, you won't get dual dual channel. Extra slots just allow you to have a greater total of RAM running in dual channel.

Number of slots is also largely irrelevant. On the NF7 for instance, with three slots, you can have 2 x 512 MB sticks in one channel and 1 x 1 GB stick in the other channel and run in dual channel mode.

 

[-=Mr_B=-]

The "early" motherboard with DC were three memory slot boards. Not four.
Not the NForce2 boards anyway.

Exacly what i said. Then we atleast know what mobo type we are looking at for sure.

Freshy, i think i understood you like "does 4 memorybanks mean i can have 2 pair of memorys, aka 2x256 and 2x512 and still run dual channel" If that is the case, then yes, you'll get dual channel, IF the mother board states that it supports it. (Most do)

If your asking if each memory get there own memory channel (quad channel memory?) then no.

Hope that is clear enough, my linguistics are slightly lacking.
B!

 

[mjw21a]

It's simply too expensive to make mainboards with more than dual channel with current memory technology as the number of mainboard traces necessitates additional layers.

Therefore we are extremely unlikely to ever see quad channel memory until FB-DIMM mainboards and RAM becomes available.

Check out my post at the following thread if you want to read more about FB-DIMMs: http://www.ocforums.com/showthread.php?p=3165838#post3165838

 

[freshy98]

It's simply too expensive to make mainboards with more than dual channel with current memory technology as the number of mainboard traces necessitates additional layers.

Therefore we are extremely unlikely to ever see quad channel memory until FB-DIMM mainboards and RAM becomes available.

Check out my post at the following thread if you want to read more about FB-DIMMs: http://www.ocforums.com/showthread.php?p=3165838#post3165838

That would really suck!

It means that if we use four mofules of the same brand and model, we would have two modules running in Dual Channel mode and two modules running in Single Channel mode each.
That would also mean I would have to go with two 1GB modules if I want 2GB in Dual Channel mode. And most 1GB modules are still only PC3200 and have quite high timings :-(

 

[nubcaek]

Heh ? I might be wrong but..if a mobo supports dual channel, you can run dual channel... unless you dont use the same chips ofcourse.

so if Id put 2x 256 (say twinmos, exact same) in dimm 1 and 3, Id get dual channel, then if Id put another 2x 256 (say corsair, exact same) in dimm 2 and 4, those 2 are also dual channel..

Im just assuming this.. since it just sounds logical to me... sorry if I mistunderstood anything

 

[freshy98]

Heh ? I might be wrong but..if a mobo supports dual channel, you can run dual channel... unless you dont use the same chips ofcourse.

so if Id put 2x 256 (say twinmos, exact same) in dimm 1 and 3, Id get dual channel, then if Id put another 2x 256 (say corsair, exact same) in dimm 2 and 4, those 2 are also dual channel..

Im just assuming this.. since it just sounds logical to me... sorry if I mistunderstood anything

It seems most logical to me too with current motherboard having a layout you described.
That is why they have the colored slots too I guess.

Having 4*512MB (in my case ofcourse) that can achive higher speeds (eq. a lot higher then PC3200 ;-) ) sounds more attractive then having 2*1GB PC3200 with high latency.

 

[nubcaek]

Yea if I were you Id go for 4x512 for the tigher timings.. though you could also consider going for 4x 256 with even tighter timings..unless ofcourse you have the money for the 4x 512 *with very tight timings*

 

[freshy98]

nubcaek, the goal for my next upgrade is 2GB of RAM so I will go for 4*512MB That is if the motherboard supports Dual Channel memory per two modules on a four slot motherboard
But I guess this is the point with todays motherboard.

I haven't really decided on memory brand and type yet.
It will be either Kingston Hyper X or Corsair XMS Pro (I like the activity LED's)
Too bad Corsair is so much more expensive. The Kingston memory I have right now serves me very well.

It will also depend on the other components.
CPU will be either FX-whateverisoutbythen, new motherboard, RAM (obviously ) and a new videocard (fastest ATI type at that moment).
Gonna get a Cascade thingy so I can mount my Cascade waterblock on the new motherboard/cpu. Also case (gonna get one this month or early next) and drives, DVD etc will stay.

 

[mjw21a]

That would really suck!

It means that if we use four mofules of the same brand and model, we would have two modules running in Dual Channel mode and two modules running in Single Channel mode each.
That would also mean I would have to go with two 1GB modules if I want 2GB in Dual Channel mode. And most 1GB modules are still only PC3200 and have quite high timings :-(

Nope, wrong again unfortunately. As soon as you go past 2 modules the board goes single channel. If you have 4 sticks, they are all running single channel.....

If you have 2 modules, they run dual channel..... Sorry, thats just the way the current boards work.

There's just not enough mobo real estate to put the additional traces required without another layer. Only the blue slots allow dual channel operation. As soon as you put any modules in the black slots, the board defaults back to single channel memory operation.

The situation you want simply wont happen until FB-DIMMs replace the current memory technology...... Wishing it was so does not make it so.... ;o)

 

[-=Mr_B=-]

Eh, seams the AMD world is a whole different place then the intel world, No dual channel intelbased mobo cares, as long as you populate the banks on both channels, it happily uses up to 4 banks / channel, meaning in theory you could have 4 memory slots for each channel, but that would limit you to 1 bank memories, and most "bigger" ram is 2, meaning they use 4 banks, on 2 slots, so 4 memories are actually both channels filled to there max, 4 banks each... Following me? Gigabyte has a habit of adding an extra memory socket, so there is 3 socket / channel on atleast "some" boards (mine for example), but they are still limited to 4 banks / channel.

My best guess is that the same goes for AMD, insane if not.
B!

 

[mjw21a]

I suppose its possible that things have changed since I last read up on this topic. I might be wrong, but I don't think so. For dual channel to work with 4 memory slots, the memory controller would need to be 256-bit.

I don't believe I've heard any hype from either Intel or AMD about a 256-bit memory controller, which would indicate they're still 128-bit and can only handle 2x slots in a dual channel arangement.