Three memory sticks

Gardinen

. I've got 2x256 mb TwinMOS PC3200 memory sticks in my computer, runnin in dual memory mode. I've would like to have 1GB of ram, but I don't wanna buy two new sets of 512 mb sticks.

Would it be possible to insert a 512 mb memory stick in the third memory slot?? Which would be 256x256x512.
How would I line up the sticks on the motherboard? In which order?

TwistedMetal

I would do...

512x256x256

I always like to put the bigger stick in the 1st slot. But, with the way motherboards are today. I honestly don't think it would even matter.

swimtech

I believe that you have to install the memory in pairs to run in dual channel mode, and it does matter which slots you put the memory in. Some boards even have nifty color coded slots - some side by side - some alternate the slots.

What make and model of mainboard is it and does it have just three or four slots?

Gardinen

Well I now that. I'm runnin the stick right now in Slot3 and 2. But would it be the performance with 256+256+512 as with 512+512??

swimtech

Honestly I would doubt it, because only two slots at a time would be used for dual channel operation. The bios would likely default, upon sensing three sticks in the mainboard slots, to some type of single channel operation for one if not all of the slots.

The information may be contained in your mainboard manual, or at the mainboard manufacturer's site somewhere mentioning what mode of memory operation is enabled depending upon what slots are used. If you can't find that information in one of those locations (and it REALLY ought to be available - that is basic stuff), you can move the memory around and bench it using Sisoft Sandra or a similar bench utility.

BWX

Fill all the slots up and tell us if it boots up in dual mode. I am interested, but actually, today I'm getting some OCZ plat. limited edition in the mail so I can test myself- but I won't be able to keep it that way because I am returning the Corsair.


And I'm pretty sure you can run 2 sticks in single channel mode by putting them in slot 0 and 1 (or whatever the first two slots next to the CPU are- the ones that are close together) but again I haven't tried that either.

G@MeBoY

It clearly says in the MB manual that for dual-channel operation you need 2 memory sticks, and depending on the mobo, you should put them in marked slots, on my epox those are two brown slots. If you put only 1, or 3 mem modules, mobo will not operate in dual-channel mode. So to conclude: 2x256 in dual-channel marked slots = dual-channel, any other combination = NOT dual-channel. AND dual-channel mode is something YOU WANT ! so adding more ram in your case, WILL slow you down ! 512MB ram is fairly enough for any kind of operation...

dipstick

Actually you can use 3 sticks in Dual Channel mode. Remember that you're still using both channels, you're just adding additional memory to one of them. I have mauals from my old NF7 and 8RDA and they both state you can use 3 sticks in 128bit mode(aka Dual Channel)

swimtech

Just looked at the manual for the NF7-S at Abit's site. If you load the memory starting from slot 3 down to slot 1 in order, the rules for creating a "memory array" will be satisfied. However, PC3200 is supported in slots 3 and 2 ONLY (up to 2G total - versus 3G total using PC 2700 or slower and all three slots used), unless there has been a bios upgrade that supercedes this specification.

So the answer to your question seems to be (as pointed out in kakarot's post above) yes, except when using PC3200 - only the slot 3 and 2 can be used to create the "array". If you add another PC3200 stick to the third slot (slot 1 - reversed isn't it? But that's what it says...), it may ignore the memory altogether and/or the "array" rules will not be satisfied. Again, an available bios update may change this specification...

Try it, bench it, see what happens - I'm curious what you find out...

dipstick

That is interesting. I checked the manuals I have and they do not say this(i have used PC3200(2x512) in slots 1 and 2 on a NF7-S before btw). They do however state you can use up to 3GB of PC2100/2700/3200 with the largest sticks supported being 1GB. At this point your best bet is to try it out before investing into three sticks.

BWX

I put 3200 in slot 1 and 3 by accident and it was still in dual mode, but it ran better in the 2nd and 3rd slot

I actually have 2 sticks of OCZ 3200 (2x256) and 2 sticks of Corsair 3200 (2x256)here I could test it with, until I return the Corsair.. but I'm not sure that would be a good idea, it says not to do it with 3200 memory.

swimtech

It shouldn't fry it though. You've already proven that by running in slots 1 and 3...

BTW - noticed Zardon has the board in his rig, nice case!