How to dualDDR with 3DIMMs?

[won]

There are only 3 DIMMs on most of the nforce2 motherboard.
Now I have 2 256MB,can I buy another 256or512MB for DualDDR?

 

[ytoledano]

You don't have to buy another stick for Dual-DDR, you can have it with only 2 sticks, just make sure that each stick is sitting on a different channel, consult your user manual to see which DIMM (slot) is using each of the channels.

Coppermine, Banias, Opteron, Prescott, Barton... How 'bout investing less in the CPU and more in its name?

 

[KrazeIke]

I think he said he already has 2 sticks. He wants to know if he can add a third stick without disabling dual channel. The answer is no.

 

[Prof133]

* Rest assured fellas, for nForce2 if 3 memory modules are inserted into the motherboard, Dual DDR is in effect. Your next best move would be to buy a 512MB stick and place it in the memory slot that seems to stand alone. Then place your two current 256MB memory modules in the two remaining slots. The result: 1GB in Dual DDR mode. So, the answer to your question is yes.

* Adding another 256MB memory module wouldn't be a good idea because some of the memory would be accessed in Dual DDR mode but a portion of it would be accessed in normal mode(64-bit access mode).


<b><font color=blue>Logic over all.</font color=blue></b>

 

[addiarmadar]

The word "dual" means only 2 stick will work in that mode. The answer is no.

F-DISK-Format-Reinstal DO DA!! DO DA!!

 

[Prof133]

Hey, addiarmadar. There are two (or Dual) memory controllers. There are two channels - one for each controller. One of the channels has two memory slots associated with it. The other channel has one memory slot. This topic has been discussed to exhaustion at nforcersHQ. Do a search for the posts of a fellow named <b>Pulsar</b> at <A HREF="http://www.nforcersHQ.com/forum" target="_new">nForcersHQ</A> on this topic. He has connections with a nVidia engineer. The answer is yes, no question about it.

<b><font color=blue>Logic over all.</font color=blue></b>

 

[Prof133]

Let's take the Asus A7N8X Deluxe nforce2 motherboard, for example. The manual (downloadable at Asus' website) reads correctly as such:

<i>To enhance system performance, utilize the dual-channel feature when installing additional DIMMs. You may install the DIMMs in the following sequence: Sockets 1 and 3 or Sockets 2 and 3 or <b>Sockets 1, 2 and 3</b>.</i>

<b><font color=blue>Logic over all.</font color=blue></b>

 

[Crashman]

It depends on what the word "dual" refers to. In nVidia's case, it refers to 2 separate channels. In Intel's case, it refers to 2 combined channels. While Intel does this to get a 128-bit memory bus, nVidia does it so that they can start a second transfer to the second bus while the first bus already has a transfer going (a type of staggering of the two). nVidia therefore doesn't require matched pairs, while Intel does. And this is OK since AMD processors couldn't take advantage of a 128-bit memory bus anyway.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[won]

Thanks!

 

[KrazeIke]

I guess that explains having dual channel despite the fact that extra bandwidth is unneccessary. I was always a little curious about that, but figured it was no more strange than running the memory at 200 on a 166FSB processor. Anyway, now I know better. Thanks for the explanation Crashman.

 

[pIII_Man]

if it is an intel processor it WILL benifit from running the memory a little faster than the fsb...on an amd cpu...no help at all...

So easy to fry yet tastes so good...
Silicon: The other, other, other white meat

 

[Crashman]

Actually no. Well, it used to be yes, but now it's no.

Intel CPUs have twice the FSB bandwidth of AMD CPUs. I doubt you'd see an improvement running the memory faster than the CPU bus on a dual channel board, but you'd definately see an improvement on a single channel board.

In fact, if you look at a typical P4 1.8GHz CPU, it has a "400" bus. A perfect match for it would be 1 module of DDR400, aka PC3200. That means your memory bus is running at twice the MHz of the CPU bus, because the 400 for the CPU bus is 100MHz x4, but the 400 for the RAM bus is 200MHz x2. Now, PC3200 wasn't available when that bus was current. But PC1600 in Dual Channel mode would have been fine too, 100MHz x2, x2 channels. But Dual Channel boards weren't out yet either!

So with Single Channel, the P4 gets more advantage from running the memory bus faster than the CPU bus, but Dual Channel takes away that need.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[pIII_Man]

very true...dual channel slipped my mind while i was typing...

So easy to fry yet tastes so good...
Silicon: The other, other, other white meat

 

[ytoledano]

No need to buy another stick, just check which DIMMs use which channels and put the sticks so that each stick is alone in its channel, I think that DIMMs 1 and 3 should do the trick but I have an Inter P4 so I can't be sure.

I had a much better usertitle but was caught trying to hack me a better one so I got my current title as a punishment