Is there a material difference between these two part numbers?

[balane]

I see G.Skill offers this RAM here;

http://www.gskill.com/en/f2-6400cl5d-nq.html

and this RAM here;

http://www.gskill.com/en/f2-6400cl5s-nq.html

Other than the heatsink is there any operating or physical difference between a 1GB stick from each?

I'm curious as to the same company would offer basically the same RAM with the same specs at different (but close) pricing.

Thanks.

 

[Quiksilver]

One set is dual channel RAM(First Link) the other set is single channel RAM(Second Link).

 

[balane]

Aha, I see that now. Must have been blind. Would you mind briefly explaining the difference to me and also, how can I tell what is in my machine now?

 

[balane]

Also, if I have 2x1GB of Dual Channel in my computer and add in another 2x1GB of memory which is Single Channel, would that be acceptable?

 

[Quiksilver]

Originally posted by: balane
Aha, I see that now. Must have been blind. Would you mind briefly explaining the difference to me and also, how can I tell what is in my machine now?

http://en.wikipedia.org/wiki/Dual-channel_architecture

Also, if I have 2x1GB of Dual Channel in my computer and add in another 2x1GB of memory which is Single Channel, would that be acceptable?

<snip>
Not all motherboards feature 256 bit memory controllers, and most of the motherboards I've seen that feature 4 memory slots still only allow 1 pair to be dual channel, the other two are locked in single channel mode or simply disabled. Odd numbered configurations obviously do not allow more than one dual channel array at a time. More often they're just 128 bit. Really be sure that the motherboard itself supports dual channel memory with 2 matched pairs, as modern chipsets do not require it on white paper specifications. A recent computer outfitted with an nForce 590 with 4 memory module slots simply runs the other bank as two single channel memory modules. As a general rule: check first that the particular motherboard supports it, server motherboards often allow multiple dual channel arrays simply because they have more than one memory controller
</snip>

Was from a recent discussion from another forum I frequent as we were having the same discussion.

 

[aka1nas]

Quicksilver is somewhat mistaken, the RAM itself is neither single channel or dual channel. The first product the OP linked is a pair of matched sticks sold as a dual channel kit, and the second link is merely a single stick of the same type.

DIMMs are always 64-bits wide. A dual-channel platform thus has a combined 128-bit memory bus. Installing 4 sticks of RAM into most consumer boards will still allow dual-channel operation as long as you are using matched pairs of RAM, but does not add additional memory bandwidth.

 

[balane]

Originally posted by: aka1nas
Quicksilver is somewhat mistaken, the RAM itself is neither single channel or dual channel. The first product the OP linked is a pair of matched sticks sold as a dual channel kit, and the second link is merely a single stick of the same type.

DIMMs are always 64-bits wide. A dual-channel platform thus has a combined 128-bit memory bus. Installing 4 sticks of RAM into most consumer boards will still allow dual-channel operation as long as you are using matched pairs of RAM, but does not add additional memory bandwidth.

I see. So, stick to stick, those DIMMs I linked to are identical?

 

[Quiksilver]

Originally posted by: aka1nas
Quicksilver is somewhat mistaken, the RAM itself is neither single channel or dual channel. The first product the OP linked is a pair of matched sticks sold as a dual channel kit, and the second link is merely a single stick of the same type.

DIMMs are always 64-bits wide. A dual-channel platform thus has a combined 128-bit memory bus. Installing 4 sticks of RAM into most consumer boards will still allow dual-channel operation as long as you are using matched pairs of RAM, but does not add additional memory bandwidth.

Partial Mistake thinks for correction. The second part is true as well, I didn't say it forces single channel on all four sticks.

 

[aka1nas]

Just to clarify, you can't run 4 sticks of RAM and have 2 running in dual channel and 2 in single channel. Consumer levels motherboards only have a single memory bus and it's either running in dual channel mode or it's not.

 

[gingerstewart55]

And it depends on the chipset and motherboard manufacturer's implementation. Take the Intel X975BX2 motherboard. It can be configured for dual channel in a couple of ways; the "normal" way and a weird way:

Two or Four DIMMs: (The "normal" configuration)

Install a matched pair of DIMMs equal in speed and size in DIMM 0 (blue) of both channels A and B. If additional memory is to be used, install another matched pair of DIMMs in DIMM 1 (black) in both channels A and B. The DIMMS in the blue and black slots do NOT have to match in size to run in dual channel mode....for instance in channel A (blue slots), you can use a pair of 1GB strips, while the other set, in channel B (black slots), can be a pair of 512MB strips.


Three DIMMs:

Install a matched pair of DIMMs equal in speed and size in DIMM 0 (blue) and DIMM 1 (black) of channel A. Install a DIMM equal in speed and total size of the DIMMs installed in channel A in either DIMM 0 or DIMM 1 of channel B. So, for instance, you can install two 512MB strips in both the black and blue slots on channel A and install a 1GB strip in one of channel B's slots, either one. This will give you 1GB in each channel and runs in dual channel mode.

The above was taken from the user's manual, linked below. It's found in the section "Installing and Replacing Desktop Board Components", "Installing and Removing Memory" subsection.

http://download.intel.com/supp...bx2/sb/d6332605_en.pdf

So, how the motherboard will run memory in dual channel mode is a lot dependent upon how the manufacturer implements it in manufacture of the motherboard.

 

[myocardia]

Originally posted by: gingerstewart55
So, how the motherboard will run memory in dual channel mode is a lot dependent upon how the manufacturer implements it in manufacture of the motherboard.

Actually, it doesn't depend on the motherboard manufacturer at all. It depends entirely upon the chipset manufacturer. That's why whenever anyone has a "can I use three sticks of RAM, and maintain dual-channel" question, we need to know what motherboard they're running (since that's always the easiest way to find out which chipset they have), before being able to answer their question. To put it another way, a motherboard manufacturer can not add features to a chipset, that weren't designed in by the chipset manufacturer (or processor manufacturer, in the case of on-die memory controllers).