Does matching RAM to make dual channel memory matter?

electroman9

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Sep 4, 2010
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I've already posted this question - but I want to make it clearer so I'm re submitting it. I haven't read a suitable response for this question elsewhere in the forums.

I want to know if matching the RAM to dual channels in the motherboard will make a marked difference in performance.

At present, OCZ are scaling back production of DDR2 ram with a view to ending the current lines. This makes it difficult for me to achieve optimum system compatibility with my existing OCZ 2GB platinum RAM module.

My motherboard is an ASUS P5QL-Pro which is dual channel compatible for two separate dual channels of memory. If I mixed RAM from different manufacturers, but using the same speed would this lead to performance problems when inserting the RAM into the 2nd channel of the dual channels?

There are two sets of dual channels in my mobo. This would mean for optimum system performance I would ideally have 1 set of 2 x 2 GB matching RAM in one of the dual channels and 1 set of 2 x 2 Gb in the other existing dual channel.

Does matching RAM make that much difference?

Or put another way, can the system utilise two different RAM modules to achieve dual channel functionality without the RAM modules being exactly the same model?

Or, to put it another way...

If I put 1 x 2 GB Kingston, 1 x 2GB Crucial, 1 x 2 GB Corsair and 1 x 2 GB OCZ inside the available slots, will my motherboard choose to ignore dual channel and run well? Will it still run as 2 x dual channel pairs even with the difference in manufacturer?

I am aware that the RAM modules should be the same frequency and speed to run well (eg. all the RAM will have to be running at 800mhz). I am also aware of the latency and timings that RAM modules from the same manufacturer and model have. I am also vaguely aware of changing timings using bios settings - however, I am dealing with this question at a consumer - rather than enthusiast or overclocker - level.

This is a matter of cost as well as compatibility. It is cheaper to buy other manufacturers RAM now that there are less OCZ platinum modules on the market. It may even be impossible to purchase these modules soon so I am wondering whether to sell my existing module and buy a whole new dual channel set. That is, if dual channel matched sets need to be as I have previously stipulated in this post.

So, does matching dual channel RAM matter? Can MOBO's that are dual channel compatible run dual channel without RAM modules matching? Should I get the abacus out of the loft and revert back to computing without a computer? I know I'm babbling now and there are far greater uses of time. Still these questions torment me and I have not been able to solve this one on my own.

Thanks for your knowledge and time in dealing with my question.

Is there
 

COLGeek

Cybernaut
Moderator
Matching memory matters when it comes to dual channel support. However, the difference between single and dual channel isn't all that huge. You are better off having enough memory, even if in single channel mode, than you are with too little memory in dual channel mode and relying on virtual memory (HDD space).

Does this help with your torment?
 

electroman9

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Sep 4, 2010
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Thanks for your relpy COLGeek. I'm still tormented - but I realised that's just me... LOL

I'm sure it's ideal to have things as recommended, however there are enough nuggets of truth that are out there on the web that show test results that show very little, if any gain from having such an ideal setup.

One such example of memory testing: http://www.extremetech.com/article2/0,2845,2328810,00.asp

That illustrates how little a benefit can be gained from increases in the speed/frequency and in having a matched dual channel pair.

In light of memory manufacturers products becoming unavailable the knowledge that one can use any type of memory as long as the speed/frequency matches would come to some relief in my mind.

However, with the concept of memory timings and the incompatibility this may cause to system stability, it leaves us with purchases having to be secure for future availability of products.

With regards to having enough memory in single channel mode - I just wish 4GB single modules were more readily available in DDR2 right now. With the move to DDR3, I can almost see 4GB single modules being ignored until it becomes standard - and by that time DDR2 will be old hat, and no one will manufacture them any more. Sounds like that Gil Bates sketch from 'The Onion Movie'...