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View Full Version : 3 sticks of RAM in Dual Channel mode?


CaptNKILL
06-25-03, 08:40 PM
IS this possible? Ive been thinking about getting more RAM for my comp. I wanted to get 2 identical (same brand) 512Mb sticks of PC-2700 so I could have a gig of matched RAM (which just seems better than my current setup.. one Samsung stick and one GIEL... which works fine for some reason). Well, as it turns out, ive sat on my ass all summer so far, rather than gotten a job, so I dont have the money I thought I would... hehehe

So... if I get more RAM, its going to have to be one stick of 512Mb. Would I still be able to get dual channel speed?

The sticks would be lined up like this:
.....3.........2.....................1
512Mb...256Mb..............256Mb

Would I run into any problems if I did this? Would it matter what kind of RAM I used if the other two are completley different already?

CaptNKILL
06-26-03, 03:19 PM
??????

ricercar
06-26-03, 03:35 PM
Best performance comes when both memory channels have the same capacity DDR. Unfiortunately if DIMMs are out of spec, then the benefits of Dual-channel DDR are compromised. So far vendors are hand-testing pairs of DDR DIMMs for dual channel use, because even top vendors don't have their run-of-the-mill DDR run dependably in Dual-channel mode!

For example, Corsair TWINX and Mushkin Dual-DDR sets are guaranteed to work in dual-channel mode, but two random sticks of Corsair PC2700 are not so guaranteed.

Theoretically if channel 1 has 1x512MB and channel 2 has 2x256MB then Dual-channel should work properly. However, all three DIMM modules have to be within x spec to work cooperatively.

...And this is where my expertise drys up.

CaptNKILL
06-26-03, 08:19 PM
soo.... if I have 768Mb in one "channel" and 256Mb in the other.... ?????

StealthHawk
06-26-03, 08:36 PM
Originally posted by CaptNKILL
soo.... if I have 768Mb in one "channel" and 256Mb in the other.... ?????

I'm pretty sure that you can't get dual channel like that....so you won't be getting optimal performance. With your original proposition, I am unsure of whether or not you will get dual channel or not :(

ricercar
06-26-03, 10:17 PM
Best performance comes when both memory channels have the same capacity DDR.

Which part of this did you not understand? :confused: Since 768 MB is not equal capacity to 256MB, therefore you won't get dual-channel performance. (You undoubtedly meant MB not Mb, but 768 Mb is not equal to 256 Mb either.)

Put a 512 MB in one channel and two 256 MB in the other.

CaptNKILL
06-26-03, 11:32 PM
Damn, I hope it works then.... last time I had the GIEL and the Samsung together (slots 3 and 2) I had stability problems. Im almost certain it was because of the RAM. Whats really dumb is that its working fine in Dual Channel mode.

Thats why I was wondering if 768+256 would work. I guess I could just buy the RAM and find out... not any time soon tho, I dont have $70 to spend to test some RAM.

john19055
06-27-03, 10:32 PM
On the N-force2 to run dual channel right the diagram that you show is correct 1st slot 512mb and in the 2nd and third slot you need a stck of 256mb in each and that would give you a Gig of ram,but I would make sure that they are the same brand and have the same cas.

Dazz
06-28-03, 05:10 PM
I have 256MB & 512MB and it indeed works in dual channel i have even tested it. You are thinking of INtel dual channel solutions which MUST have all DIMM's the same size.

john19055
06-29-03, 12:30 AM
I am thinking of the N-force2 board and all the promblems I have seen at Nforcershq.com when people have used different brands and different sizes in the board and they was wondering why they had crashes ,BSOD and some would'nt even boot up.I was just saying that is the proper way to set it up according to the book and the companay,to have the least problems,Sure I have heard of some useing a different brand for each slot and it work,but they were more people that had problems when they did that. But good look maybe yours will work fine.

Dazz
06-29-03, 03:02 AM
I am running 256MB Crucial PC2100 & 512MB TwinMOS @ 266MHz CL 2/2/2/5 perfectly stable, hell i have NEVER seen disk scan since i formated the computer 3 weeks ago. The only reason i had to format was due to replacing my board and kept on BSOD me everytime it tried to load in Windows XP. AMD and VIA drivers i belive was the cause of it. But my computer has never been unstable since i got it :) Unless i overclock but thats due to my polly XP2100+.

PenguinJim
06-30-03, 01:57 AM
Are you SURE you're running in Dual-Channel mode, Dazz?

Dazz
06-30-03, 02:35 AM
Pretty sure beacuse at POST it says Dual Channel enabled. and i get some good memory scores in SISoft so i belive so :)

That was with 512MB DS, 256MB DS & 128MB SS.

PenguinJim
06-30-03, 02:38 AM
I'm convinced :)

Pretty freaky though.... your computer is now like an airplane. It shouldn't work like that, but it does. Crazy stuff, man, crazy.

Write a paper on it and get it published.

Dazz
06-30-03, 03:00 AM
I just wanted as much memory as possible 900MB :D , although i didn't keep it in as thats for the other computer i am selling, also the last time i mixed single and double sided DIMM's it wasn't all that stable with my AMD 760 board :o