RAM question

[TahoeMax]

I'll soon have 2 gigs of RAM: 512MB of Kingston value RAM, 512MB of Corsair value RAM, and 2x512MB Corsair dual-channel value RAM. All of it is PC3200. I just want to know if i can run all this at once and have the dual-channel running in dual-channel mode without the single-channel sticks screwing things up.

Thanks!

 

[bamacre]

All DDR memory can run in dual channel.

 

[TahoeMax]

Originally posted by: bamacre
All DDR memory can run in dual channel.

well, that shows how informed i am. that's fantastic, then

how come some kits advertise themselves as dual-channel, while others don't? just for attention?

 

[kylebubp]

Pretty much, I mean, they sell them in packs of two and call them dual channel, but really dual channel capabilities are determined by the motherboard. Consult your manual to see how to install your memory in the correct slots and order.

 

[zagood]

Make sure they're both either single sided or double sided. I've seen problems with ram from dif. manufacturers trying to run in dual channel even if they were both single/double sided and had the same basic specs, so don't automatically assume that it's going to work.

Dual channel kits aren't exactly a marketing ploy, but they're guaranteed to work in dual channel mode.

-z

 

[TahoeMax]

i actually don't think my question ever got answered...

if i have one set that will definitely work in dual-channel and another set that doesn't, can i run 1 gig dual-channel and 1 gig single? or must i run it all single-channel if not everything works together?

how different is dual-channel from single-channel, anyway?

 

[JimPhelpsMI]

Hi, DDR stands for DOUBLE DATA RATE. That means that if your MB can handle it Memory is accessed twice on one memory read cycle. Once on the rise and once on the fall of the Read Pulse. Search for Dual Channel and I think you will only find explanations of Double Date Rat. Good Luck, Jim

 

[BUrassler]

You cant have half your system's RAM running in Dual Channel and the other half not. It is one or the other.

 

[stevty2889]

Originally posted by: TahoeMax
I'll soon have 2 gigs of RAM: 512MB of Kingston value RAM, 512MB of Corsair value RAM, and 2x512MB Corsair dual-channel value RAM. All of it is PC3200. I just want to know if i can run all this at once and have the dual-channel running in dual-channel mode without the single-channel sticks screwing things up.

Thanks!

Dual channel is a property of the memory controller, not the memory itself. You can't run half dual channel, and half non-dual channel. As long as you are using pairs, and your motherboard supports dual channel, you will run in dual channel. Memory thats sold in dual channel kits, is just a marketing scheme. It's two sticks of the same memory, that are packaged together, and theoreticly tested together in dual channel mode. As long as you buy to sticks of the same thing, they will work in dual channel. You could have 2 sticks of corsair, and 2 sticks of kingston, and it would work in dual channel, as long as you keep the pairs matched. It's best to have all sticks the same however, as all the memory will run at the timings of the slowest sticks.

Also, depending on what CPU you have, 4 sticks might have to run at 2T timings, and PC2700(DDR333) speeds.

 

[imported_Imp]

Well the Ram will either work in dual channel or single channel which is pretty much determined by the memory controller onboard the CPU (AMD) or motherboard or something. Only reason there's dual channel memory is that they are tested in dual channel before being sold (they SHOULD be perfectly matched sticks which Corsair at least recommends). Since it's all valueselect, you should be good to go, except VS modules come in Cas 3 and Cas 2.5 flavours. I had the misfortune of mixing them up and now I can't run at DDR400, but it does work in Dual channel...eh?...

 

[TheRyuu]

It's determined by the motherboard.

Dual Channel Packes that you get in the store are just for markating (and sometimes can be cheaper then getting 2x the single pack one.

 

[fire400]

generally, the RAM sticks must be the same model in both RAM banks.

 

[Matthias99]

Originally posted by: fire400
generally, the RAM sticks must be the same model in both RAM banks.

Actually, it shouldn't matter in the least. All it has to do is run at the same speed and timings, and possibly also be the same chip density. The 'model' is just an identifier string written into the SPD, if even that.

Someone else here (don't remember who) was claiming to have even run with a mix of single-sided and double-sided DIMMS in dual-channel mode on an A64 successfully. It's all up to the memory controller.

 

[Googer]

The number of channels is not a property of the DIMM or RAM Stick it's self. Your motherboard determines how many channels of ram. One stick of ram is needed for each channel. Each channel gets it's own memory controller. Single channel has only one memory controller while dual channel has two controllers. Quad or even octo-channel ram (4 or 8) is possible if they install four or eight controllers in each computer. The avalable bandwith will increase with each memory controller.

Although it's not the most deireable situation, It is possible for a single memory controler to control more than one stick of ram. A computer with two memory controllers and 3 sticks of ram will run but only in single channel mode due to the unbalance.

 

[Jeff7]

Originally posted by: TahoeMax
i actually don't think my question ever got answered...

if i have one set that will definitely work in dual-channel and another set that doesn't, can i run 1 gig dual-channel and 1 gig single? or must i run it all single-channel if not everything works together?

how different is dual-channel from single-channel, anyway?

To answer directly:
RAM is RAM. There isn't dual channel and single channel RAM. It's just marketed as such, and we all know that marketing doesn't have to mean a damn thing in the real world.
RAM's channels are controlled by the memory controller, and the slots the RAM is put in. Some RAM goes in one channel, the rest goes in the other. Two channels for RAM communication = dual channel.
I've got 3 sticks running dual channel, 2 x 512MB in one channel, 1 x 512MB in the other. I've also run a stick of 512 and a stick of 256 in one channel, and 512 in the other. Worked just fine.

How different is it? Depends on the motherboard's chipset. I know that back in the nForce2 days, dual channel only added a few percentage points to benchmarked RAM speeds. It did help a bit more though when using nForce2 IGP - the integrated graphics could have its own channel to communicate more rapidly with the RAM.
I don't know how it is now with the newer chipsets. I'm in college, so I won't have money for upgrading for a few years; no sense following the market closely.

 

[Yeormom]

Have you ran any performance tests on your memory in different varations to see if there is any speed difference at all?