i got DDR, maybe TDR?

[stadion1]

Ok, I understand DDR, and timings vs. bandwidth, and all that stuff. What I'm wondering is, what happens when you add a third stick?

My mobo manual clearly states which slots to use for DDR. I don't remember which ones off the top of my head, but it's pretty standard. slots 1 and 3, or slots 2 and 3, etc. But many mobos I've seen including my own list slots 1,2, AND 3 as an option for DDR.

When you fill all three slots with matched sticks, how does the system organize the ram? A matched TRIPLET? Since there is no such thing as TDR, you're still in DDR.......two operations per cycle........three sticks........two operations per cycle........help? anyone?

I mean do two sticks send together and one alone? Or can the system divide the clock into thirds and I just never heard about it!?!? (doubtful)
Thanks

Mark Casey

 

[pIII_Man]

on most boards the motherboard/chipset only uses one memory controler. Boards using dual channel memory interface effectivly double the memory bandwith by using 2 controllers...

So if you are using 3 sticks of ram in a mobo with dual channel, as long as the amount of memory feeding each controler is ballenced (ie one controller gets 2x 256mb and the other gets a 512mb stick) u will be running an effectivly 256bit bus, thus doubling your bandwith. Of course on a board with one mem controller no matter how many sticks you use u will not double, tripple etc. your memory bandwith.



If it isn't a P6 then it isn't a procesor
110% BX fanboy

 

[HammerBot]

If you run single channel DDR, any additional stick simply gives you more memory at the same speed.
If you run dual channel DDR, memory modules must be added in equal sized pairs. Anything else wont work.
If you run dual channel DDR on two modules and add a third, either your mobo wont use the third, or all three are reduced to single channel mode.

<i><b>Engineering is the fine art of making what you want from things you can get</b></i>

 

[Johanthegnarler]

I ran into a problem, when i built this computer i bought 2x256mb of mushkin lvl 2 pc3500. Now..The memory itself is awesome.. but i went from a 1gb rdram pc800 to 512 ram and sadly i have gotten used to it.
So, now i want 1gb of same memory, but i know i'm screwed becuase nf7 will run all 3 in single channel mode if i add another 512 stick.
So... if anyone wants to buy perfect condition mushkin lvl2 memory off me let me know. i need a gig.
Running SWG and it's constantly using my harddrive VM.

<A HREF="http://arc.aquamark3.com/arc/arc_view.php?run=610166081" target="_new">http://arc.aquamark3.com/arc/arc_view.php?run=610166081</A>
Figured i'd do it too..reality my ass.

 

[stadion1]

I'm going with 'PIII Man' on this one. The manual says, and I quote, "To enhance system performance utilize DDR feature when installing additional DIMMs. Install the DIMMs in an of the following sequence: Sockets 1&3 or Sockets 2&3 or Sockets 1, 2, & 3."

When I look at the board...two of the sockets are closer together than the third...sockets 1 and 2 that is

I assume socket 3 is one channel....it is further away than sockets one and two. So if you put sockets 1 and 2 in a channel called 'L'.....and socket 3 in a channel called 'R'

then sockets 1 & 3 == L & R
2 & 3 == L & R
1,2,&3 == L L & R

why couldn't it combime 1,2 in a single channel IF they equaled socket 3 in speed, capacity, and timing?

and why else is the 3rd socket twice as far away as 1 and 2 are from each other

makes sense to me......and besides I just tried it and it worked

thanks for the idea to try PIII

 

[Prof133]

when i built this computer i bought 2x256mb of mushkin lvl 2 pc3500. ... So, now i want 1gb of same memory, but i know i'm screwed becuase nf7 will run all 3 in single channel mode if i add another 512 stick.

If three memory modules are installed, DualDDR is in effect. Place the 512MB memory module in the memory slot that seems to stand alone and the two 256MB memory modules in the two remaining slots.

 

[Johanthegnarler]

ARe you absolutely positive of this? Becuase i heard of people not being able to run dual channel with memory in all three slots.
But.. i hope your right. I'll be so damn happy.


<A HREF="http://arc.aquamark3.com/arc/arc_view.php?run=610166081" target="_new">http://arc.aquamark3.com/arc/arc_view.php?run=610166081</A>
Figured i'd do it too..reality my ass.

 

[Prof133]

May want to check out nVidia's doc on nForce2 memory architecture. There has also been a lot of discussion about this at <A HREF="http://www.nforcershq.com/forum" target="_new">nForcersHQ forum</A>.

 

[Johanthegnarler]

Thanks, becuase it would save me a lot more money to just buy a stick of 512 instead of re-buying 1 gb in 2x512.

<A HREF="http://arc.aquamark3.com/arc/arc_view.php?run=610166081" target="_new">http://arc.aquamark3.com/arc/arc_view.php?run=610166081</A>
Figured i'd do it too..reality my ass.

 

[stadion1]

I don't know about newer RAM, but I put 128mbx2 PC2100 in slots 1 & 2 and a similar 256mb PC2100 stick in slot 3 and it at least said it was using DDR. I just took it out after that, I didn't check it in the OS, I assumed BIOS knew what it was talking about. (for once) (A7N8X non-dx)

Also these were off brand sticks, I'm not really sure where they even came from. However the part number on the 128 sticks is the same as the part number on the 256 stick except for an added "128" or "256" in the number. So the sticks may have to be extremely similar.

Someone with newer hardware should further test this, if they haven't already. I'd be interested in hearing about it.

 

[Johanthegnarler]

Although i'm not entirely sure, it looks like i might have to be a guinea pig and possibly be the one to test it.

<A HREF="http://arc.aquamark3.com/arc/arc_view.php?run=610166081" target="_new">http://arc.aquamark3.com/arc/arc_view.php?run=610166081</A>
Figured i'd do it too..reality my ass.

 

[stadion1]

well I wouldn't say that...it seemed to work for me, and I asked around and a guy i trust told me that he has for sure seen it work in OS and everything.

besides why the friggin else are the slots not all just close, side by side