Dual-channel vs Tri-channel for DDR3

[vwilson]

Is DDR3 dual-channel vs. tri-channel a marketing issue or is it a technical issue?
I see DDR3 Dual-channel kits (2x2GB) marketed for AMD based motherboards.
I see DDR3 Tri-channel kits (3x2GB) marketed for Intel i7 based motherboards.
Can I use the memory interchangably, keeping in mind AMD in pairs, Intel in triples?

For example: say I have two ASUS M4A785TD-V EVO motherboards (AMD chipset, AMD Phenom II X4 955 CPU) and two G.Skill F3-10666CL9T-6GBNQ DDR3 Tri-channel Memory Kits.
Can I put two DDR3 sticks on one motherboard (4GB) and four DDR3 sticks on the other motherboard (8GB) and everything work properly?

[Tradesman]

Technically speaking, it's a technical issue (lol) as well as a marketing issue.

Single channel operates at 64 bit wide, dual channel at 128 bits wide, and tri is at 192 bits wide data channels.

At this point in time though, I feel it's more of a marketing ploy that a true technical advance for the current lineups of CPUs. AMD can't handle it and in what testing I've done and seen tri channel shows no marked increase in overall speed/bandwidth than dual channel, in fact, dual channel will often outrun tri channel.

Reasons: (IMO) The i5/i7 MCs are still immature (to a point), and also that mobo BIOSs still aren't up to snuff with tri channel.

You can pretty much use the sticks however you want, with a tri set you can use individual or 2 at a time or all three at a time, and for the most part you can buy tri and use it in an AMD box or buy dual aimed for AMD and use it in an Intel box, you will either be lucky and have it work out of the box, or you may have to play w/ timings and voltages a bit.

Tman

[vwilson]

Tradesman,
Thank you for the quick reply.
If I understand you right, and correct me if I'm wrong, a DDR3 DIMM is a DDR3 DIMM and can be used in either single-channel, dual-channel or tri-channel configurations. The marketing verbage on the packaging that says "DDR3 Tri-Channel for Intel i7" or "DDR3 Dual-Channel for AMD" is just that, marketing verbage intended to sell two at a time or three at a time (keeping in mind the DIMM voltage requirements of Intel vs AMD).

Thanks again.
VW

[Tradesman]

Basically correct, the sticks are 'tested' and programmed to worked together as the set sold. One sorta nice thing about them, i.e. if your going to split the sticks between boxes would be if you have say a tri-channel set of 3x2GB w/ timings of 9-9-9-24 and you pu 1 stick in a box and the other 2 in a second box, it should/will be easier to tighten up the timings to maybe 8-8-8-21 or even better..........for all that's worth. You see a lot of hype about people tightening up the timings beyond spec, but thats more of a bragging rights thing than anything else, it's not generall anything you'd be able to telljust sitting at a computer, to a lesser degree same with RAM speed. If i were to put you in front of two identical systems running either different RAM timings or RAM speeds i.e. 1066 vs 800, or 1333 vs 1066, (and I've done this with high end users) you'd prob be guessing if you say you could tell a difference without running a benchmark or looking at the setup.

[GSKILL TECH]

TMan covered a lot.

You got it right though.. "a DDR3 DIMM is a DDR3 DIMM"

The main differences are memory voltage, and possibly some compatibility issues.

If you have a DDR3 module that operates 1.8V at its rated spec and it was originally for AMD dual channel, you wouldn't want to use it on Core i7 platforms since Intel states a 1.65V memory voltage limit for their platforms or it could damage the processor.

A recent/positive example is the new P55 RipJaws that we have available. Although they were specifically made for the P55, or you can say "marketing verbage", the specifications also fall within AMD platforms. 1.5V-1.6V. But for example we had an issue with the CL7 versions because the timings were too low for some motherboards.. but with a little BIOS tweak, that has been solved now.

The general rule of thumb is to stay with what is made for your platform, but if you really want to stray off, simply ask us and we'll be happy to answer that for you. We do not guarantee it nor suggest it, so if you have compatibility issues, what can we really say?

Especially in your type of case where you have motherboard just not memory, simply purchase the correct memory. The triple chan NQ arrangement you ask may be doable, but why do that? Your combo deserves some low latency RipJaws. That's a good board and processor that should be fully utilized. I would recommend the 1333 CL7 RipJaws or 1600 CL8 as they have proven to provide very good performance results.

Thank you
GSKILL SUPPORT