Dual Channel Memory Question.

[mtnagel]

I'm thinking about getting the Asus A7N8X-E mobo with the AMD XP 2500 chip. I was looking on the Kingston site for which RAM to get and it says "MODULES MUST BE ORDERED AND INSTALLED IN PAIRS for Dual Channel mode. Kingston offers "K2" kit part numbers for Dual Channel mode. "

I have no idea what this dual channel mode is.

I was thinking of starting with just 256 mb (I don't play games) and then adding another 256 mb when I find a good sale. Will I have a problem? Will I have to buy 2 of the exact same memory sticks? Do they have to be same manufacturer or just same specs?

Thanks for helping a newbie build his first computer from scratch (I've upgraded my previous two a lot).

Matt

 

[wraith3k]

Dual-channel mode just gives you better performance, but you have to use 2 sticks at a time for it. If you don't care about that, then one stick will work fine. When you do eventually get another stick later though you'll get dual-channel anyway because you'll have two sticks total, as long as they are put in the correct slots.

The Kingston K2 part numbers just indicate that the kit is two sticks that are sold together. If you buy two separately that works just as well.

But if you just want one stick of 256 to start with that'll work too.

 

[mtnagel]

Thanks.

When you say "better performance," how much are we talking?

 

[Odeen]

For nForce2 chipsets - about 2 to 5%. The Athlon XP can't use much more bandwidth than a single DDR channel affords it, but it can benefit some through prefetch (The chipset "guessing" what data the CPU will need next and retrieves the data using this "spare" bandwidth)

You have the capability in the chipset, you may as well use it.

 

[JPierce]

I was thinking of starting with just 256 mb (I don't play games) and then adding another 256 mb when I find a good sale. Will I have a problem? Will I have to buy 2 of the exact same memory sticks? Do they have to be same manufacturer or just same specs?

Thanks for helping a newbie build his first computer from scratch (I've upgraded my previous two a lot).

Matt

It is recommended to buy matched pairs (two identical sticks) of DDR for dual channel boards.

 

[Concillian]

Originally posted by: mtnagel
Will I have a problem? Will I have to buy 2 of the exact same memory sticks? Do they have to be same manufacturer or just same specs?

Thanks for helping a newbie build his first computer from scratch (I've upgraded my previous two a lot).

Umm, maybe.

Most modules will work fine in dual channel, however some single modules you buy will not work fine in dual channel. I have 2 512MB sticks that will not work in dual channel with anything. but I have several single sticks that will work fine in dual channel.

From the single sticks (not sold as dual channel) I own:
2 512MB sticks do not work

2 512MB sticks do work
4 256MB sticks do work

In my case the sticks that don't work don't work with ANYTHING in the 2nd channel. The sticks that do work will work with any brand or type of memory in the other channel.

I have also run 2x256 in one channel and 1x512 in the other and seen benefit from dual channel. So in my experience the 'exact same memory' is a CYA tactic. However memory not sold as dual channel may not work as dual channel. All the dual channel sets I have used (2 sets of 2x512 and one set of 2x256MB) obviously work in dual channel, with each other OR with the single DIMMs I listed earlier.

 

[orangat]

Concillian,
Could it be that the DIMMs that don't work might be double sided instead of single sided or vice versa?

 

[EglsFly]

I originaly had 1 stick of Corsair XMS 512MB, many months later purchased another stick of Corsair XMS 512MB and it worked fine.

 

[Concillian]

Originally posted by: orangat
Concillian,
Could it be that the DIMMs that don't work might be double sided instead of single sided or vice versa?

All my 512MB sticks are double sided. 2 of my 256MB stics are double sided.

It's not a double side/single sided thing. It's the particular sticks of 512MB. They both happen to be Kingmax, but 2 of the 256MB sticks that DO work in dual channel also happen to be Kingmax, in fact the same speed/type of Kingmax memory, just 256 instead of 512MB (single sided instead of double sided).

The single 512MB sticks that work are both double sided. As were the two 1GB dual channel kits I've owned (one of which I traded with a friend and no longer have).

 

[kxm9976]

hello

will sticks coming out of a dual channel kit work together in a single channel mode on (like for AMD 64, socket 754)?
And are they the same ram sticks as the ones sold separately?

Thanks a lot

 

[Concillian]

Yes, dual channel kits work fine single channel or alone.

As far as I know they are regular single sticks paired up. Whether they go through specific testing or not, I have not a clue?