dual channel, but three slots?

[jurtje]

I have an asus a7n8x-e deluxe which has an n-force2 chipset and thus allowing me to run mem in dual channel mode. I have 2*256 mem now, but I was wondering in case of an upgrade, what do I put in the third slot?
Another 256 mb with the same specs, a 512 mb? Or doesn't it matter, because the third slot works in single mode?

I don't get it

[striker777]

I don't get what you are talking about. According to your manual all the slots are dual channel but if you have 2 dual channel sticks you are supposed to put them in Slot A1 and B1 or A2 and B2. So I would go with a big a stick as you can afford, that runs at the same CAS and speed as the other sticks.

[playafly187]

if i am not mistaken, you can only run dual channel mode with two sticks, in the slot A1 and B1, as striker777 referred to. if you add a third stick, you will of course have more memory, but also you will no longer be in dual channel mode.

[silenze]

The slot set apart from the other's is a separate channel, and dual channel needs matched sizes to work, so if you filled all 3 slots even with the same chips, it would probably disregard the set apart dimm slot, and go with the 2 chips on the other channel..

[striker777]

What a bunch of crap. It's like we are back to the 'ole pentium days where you had to install ram in pairs and stuff. Geezzzz....Still though the Asus Manual showed a setup with 3 sticks listed under the Dual Channel category. I really don't know though, I haven't looked at Dual Channel yet so I'm just going by what the manual is "showing" but not saying.

[silenze]

Dual Channel is only a 5% increase over single pretty much across the board, so stuff all 3 slots and see how much registers :twisted:

No really; I don't know, but now I'm curious so I'm scowering the intarweb.

[MASSiVE]

that should work in theory, i know some where it did and others where it didnt, first of all make sure the 3 sticks are from tesame brand, and if you have 2*256 in dual already you should put a 512stick in the third slot coz ive heard that a 256 didnt work in many cases, make sure theire all rated tesame MHz and timings and try :wink:

[silenze]

I thumbed through my old msi k7n2-l booklet sitting here.. in the diagram it shows a max of 1gb per DIMM#, and a max total of 3GB, so using all 3 has to work as single channel, just use matched chips.

[fstroupe]

The third slot is mainly for upgrade...i.e you started with 2x256, so you put a 512 in the third slot for upgrade to 1 gig dual channel. If the same size is in all three (or smaller one in one slot) it runs in single channel.

Some boards (including my NF7-S) will only support 2 gigs of PC3200 or better, 3 gigs of 1600/2100/2700.

The real pain is trying to figure out which slots to use...they are not the same between manufacturers. Abit recommends you start in DIMM3 (which is the slot that is seperate from the other two) and go towards DIMM1...so DIMM1 is the "3rd" slot. This is one of the biggest causes of "stupid newby questions" at the nForce2 and AMD based forums. I guess it probably has something to do with translating from Asian languages to English...you should read my mobo manual...the translation is horrible.

Anyway, to answer your question, put a 512 in the third slot, preferably the same speed as your 256's, and you will be running in dual channel.

[fstroupe]

Did a little research on your board....this is from the A7N8X FAQ at the nforcers.com forum: (I did an immense amout of research before buying my Abit, and the A7N8X-E Deluxe was my other consideration...and I joined probably 10 forums during my research)


Q. What slots do i put my memory in to enable Dual Channel DDR (TwinBank)?
A. The manual says for 1 stick to reside in each channel. What that means is to benefit from DCDDR you should place modules in slots 1 & 3, or slots 2 & 3. Slot 1 is located closest to the Ziff Socket (black in color) slot 2 is next (blue) and slot 3 is next (also blue). Using all 3 slots can also enable DCDDR. People’s results have varied from system to system depending on what slots they put their modules in. Some get better performance with a certain configuration and some get better stability with another. You should try your own tests as they will more then likely differ from others.

Q. How do I set up Dual Channel DDR/TwinBank/DualDDR optimally?
A. In order for DualDDR memory to run at it's optimal speed, you need to have an equal amount of RAM in each channel. Slots 1 and 2 are channel 1, and slot 3 is channel 2. Right now I've got 256MB in slot 2, and 256MB in slot 3. This means 256MB in each channel. If I was to upgrade and wanted to keep full Dual DDR, I would need a 512MB stick, and put it in slot 3, and the 256MB sticks in slots 1 & 2. This would give me 512MB in each channel, and an equal balance. This would give me an optimal Dual DDR setup.
If I were to have, say, 512MB in one channel, and 256MB in the other, only 256MB of the channel with the 512MB stick would be running in Dual DDR, since the channels would not be balanced. The rest of the 512MB stick would run in standard single channel mode, giving below optimal performance.

Personally, I think that this is a stupid setup. Most people would think that you would put 1 DIMM in a blue slot, and one in a black slot, and have dual channel, including myself. 'Course, I'm one of those guys that usually read the manual LAST! :roll:

[Beemer]

Things come with manuals?? Are those the little glossy books I always throw aside as I tear into the package looking at my new toy? 8)

[KryoNexus]

Things come with manuals?? Are those the little glossy books I always throw aside as I tear into the package looking at my new toy? 8)

the Abit manuals are worth a reading IMO. You can find out alot about the various options in your bios from it. Which will result in you making changes to make your computer faster. ;-)

[Beemer]

Or I could just ask you. :wink:

[KryoNexus]

yeh, that seems to be the norm

[Beemer]

I cant help that I like interaction. Reading is just too one sided.

[KryoNexus]

I cant help that I like interaction. Reading is just too one sided.

you should try turning the page over and reading the other side ;-)

[Beemer]

Well, I do sometimes, but they never answer my questions. I guess my questions just arent asked frequently.

[silenze]

I think they majorly screwed up and should've put 2 DIMMs for each channel, so we all didn't scower the web trying to figure out their nonsense :P

[fstroupe]

The Abit NF7 manual is pretty complete, I guess, though I personally feel that the troubleshooting section leaves much to be desired.
Beep codes are not even mentioned, much less defined. I assume that the codes may be different with different bios, but they could at least let you know that troubleshooting is possible using these beeps.

[silenze]

My MSI k7n2 delta-l manual is decent, it showed all channels with a max of 1gb, and they can all be filled in any order, but it didn't bother to mention if it would be dual or single or what..

makes sense now though, dual channels, period.

[playafly187]

i am about 99.9% sure that once you add a 3rd stick, the dual channel feature goes away.

[silenze]

It is the question, you know it just as I once did, what is the ma.. er... oh.. yeah I wonder .. hehe

[silenze]

Found it:

"Q: How do I use Dual Channel? (#9219)
A: Dual Channel requires at least two modules for operation. It is recommended that the modules you use be of the same size, speed, arrangement etc. Dual Channel is optional on the original nforce2 motherboards and nforce2 ultra400. You can choose to run in single channel mode on these motherboards. (Nforce2 400 boards are singe-channel only).

Most dual channel capable nforce2 motherboards come with three slots. On these motherboards the first memory controller controls only the first slot (or the slot by itself), while the second memory controller controls the last two slots (which are usually closer together). Name them slots 1, 2 & 3 respectively. To implement Dual Channel, it is necessary to occupy the slot 1 (channel 0) and either one of the two slots that are closer together, slots 2 or 3 (channel 1) The entire config would be running in 128bit mode.

You can use three modules in Dual Channel Mode, by filling the third unoccupied slot. With three sticks, slots 1 remains as channel 0 while slot 2&3 become channel 1. To maintain 128-bit mode, with all three slots filled, each channel must have an equal amount of memory. For example, slots 1 should be filled with a 512Mb module, while slots 2 & 3 are populated 256Mb modules. If you were to use three modules of the same size, then only first two modules would be running in 128bit Dual Channel Mode. Example, using 3x 256Mb modules will have the first 512Mb running in 128bit Dual Channel mode, while the remaining 256Mb will be in 64-bit Single Channel mode.

Intel dual-channel systems are different. The have either two or four slots, and to run dual channel mode must have either one or two pairs of (hopefully) matching modules. Running three modules on a P4 system will force it to run in single channel mode, and is therefore to be avoided.

Consult your motherboard manual for instruction on exactly which slots exactly to use.
"

[siq]

I knew that. :lol:

[silenze]

It's goofy I tell you what... I never intended anything but a matched pair for mine *shrug*

[Beemer]

I hope for two matched pairs, yeah so its over done 2gig pc4000 *drool* as my grandfather once told me "No use bein a feller unless your going to be a hell of a feller"

[silenze]

Well you're preparing for the future atleast. :)

[jurtje]

I'm glad to see I can make you guys discuss!

Anyway, I think knutsaac's and silenze's answers make the most sense, on each channel the same amount of mem.

Thanks guys!!!

*thinking of new difficult question*

[playafly187]

suppose i was completely wrong..l ol

[striker777]

OCIA.net does it again.

[MASSiVE]

like i said; put a 512 stick in the other slot :wink: you didnt read my post? :P

[Roadracer_4ever]

I run the Nforce2 Ultra400 chipset on my board, and it uses the first(seperated) and either one of the other two slots for dual channel mode. I found it didn't like having 3 sticks of RAM installed, even in single channel mode, so I sold the extra stick with my old motherboard. Not so sure I want to run out and blow moeny on a 1 gig shim of ram just to see if it would blue screen in dual channel mode with my current 2x512 configuration. It's also been my experience in the past that other motherboards don't seem to like 3 sticks of ram(at least not ddr ram) installed, I've always had problems with blue screens and constant reboots and errors... It's possible it was just a heat issue, but I've also talked with a few pc techs at various computer stores and they've said much the same thing....most boards don't seem to like 3 sticks installed....just run the two biggest sticks you can afford. Be aware as well that some boards default to a lower FSB with a third stick of ram installed, (not sure if this applies to dual channel chipsets or not) so check your manual. IMO i would personally run 2x1gig sticks(if it's in your price range). On the other hand, if you're looking at overclocking, smaller modules tend to run cooler and more reliably.....JMT

[Roadracer_4ever]

To explain my last post a bit better in regards to most mobo's not liking three dimms of ram, and more importantly aimed in explaining the dual channel ddr aspects of the Nvidia chipset, check out this link

[http://www.gamepc.com/labs/view_content.asp?id=nforce2tech&page=1]

It explains in great depth how it all works, well written and worth the read.

[Roadracer_4ever]

Ok...to ask a n00b question.....how do I make links clickable?

[fstroupe]

... just plain gettin in the box and working .... :roll: LOL

When you go to the "post" screen, there is a line of buttons across the top, under the "subject" line. Click the "url" button before pasting the link, and again after. Though, if the link is the last thing in your post, when you "submit", for some reason it adds a second "url" tag, and it doesn't work. I usually "preview" instead of clicking the button a second time.


[/quote]

If you notice the stray "quote" tag, that is an extra one tacked on like I was talking about.

[Roadracer_4ever]

I posted that n00b question, and then figured it out on one of my next few posts on another topic....lol

[bgeh]

well if i do remember correctly, intel and nVIDIA's implementation of dual channel is different, in nVIDIA's case, you can have dual channel with 3 slots provided equal amounts of memory is placed in each controller e.g
Controller 1 = 256mb + 256mb
Controller 2 = 512mb

while Intel's implementation is sticks must come in a pair or bust......that's if i do remember what i read longggg ago :lol:

[figgy2967]

just set the duals to the two highest ports