G Skill 2 x 4gb ram compatibility with ASUS Sabertooth X58 mobo and i7-950?

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I would discourage you from using Dual Channel Kits on any Tri Channel MOBO. Even IF they work you limited your upgrade path to another Dual Channel kit. {see image} And NO, you cannot buy 3 Dual Channel kits and know they'll work together.

Therefore, I would first recommend Corsair Dominator TR3X6G1600C8D 3X2GB, or CMP12GX3M3A1600C9 3X4GB.

Configurations: {Dual vs Tri Channel}

Got it, thanks for the help.

I just wanted to follow up on this thread...

Ok, so I did go ahead and install two sticks (2 x 4gb) of dual channel G Skill Ripjaws DDR3 1600 RAM (9-9-9-24) on the ASUS Sabertooth 1366 x58 motherboard in the first two tan colored channels and when I booted the PC for the first time Speccy indicated all 8gb were running fine and at 1333 by default (at 9-9-9-24). So I then went into BIOS and changed to XMP and it auto selected Profile 1 running the RAM at 1600, then Save & Exit. After the PC finished booting I ran Speccy and it indicated the 8gb of RAM was now running at 1600 (9-9-9-24).

Several days later I ordered a 1 x 4gb stick of the same G Skill Ripjaws DDR3 1600 RAM (9-9-9-24). Before I installed it I set the RAM setting in BIOS back to Auto, rebooted, and it showed up in Speccy at 1333 again. I then shut down and installed the 3rd stick in the 3rd tan-colored slot and booted and the PC booted, found all 12gb and Speccy showed it running at 1066.

I then shut down, started up and went into BIOS and went back to the XMP setting and it again auto selected Profile 1 running the RAM at 1600, then Save & Exit. After the PC finished booting I ran Speccy and it indicated that all 12gb of RAM was now running at 1600 (9-9-9-24).

The only thing I noted in Speccy after all this was about a 1oC to 2oC increase in CPU temp and motherboard temp.

The G Skill Ripjaws RAM - 2 sticks ordered as a dual-channel kit and 1 stick orderd later as a single stick - seems to have all been compatible enough to work together in my case for this build.

So my last two questions on this thread -

[1] Is it the case then that by buying a triple-channel kit you just are reducing your chances of incompatibility, whereas if you buy 2 then 1, or 1 then 2, or 1 then 1 then 1 stick of the same RAM that you have a higher chance of incompatibility but it still could work fine (as it looks like is the case with my build)?

[2] What are the mfr's doing to decide which RAM sticks to sell as singles, dual-channel or triple-channel, are they testing each stick in some way that tells them these two and those three will more likely work with each other, but that single won't?

What's the use now?!

1 & 2 RAM is indeed BIN Sorted; the RAM is tested after it's assembled and placed into Sets by Testing. The sets can be Dual - 2 or 4 sticks, and Tri - 3 or 6 sticks. Incompatibility in the sense of Sine wave timings; it's similar but not the same as buying high-end matched speakers. However, in RAM you're dealing with billionths of a second. NO! - the sticks do not operate the same coming-off the same EXACT line; hence the BIN Sorting. The Singles typically are the runts of the litter and have the poorest or 'oddball' BINs.

In addition, the PRIMARY advantage of Tri Channel is its ability to process 3 sticks of RAM simultaneously per cycle which you now won't have running Dual and worst if you pop-in a third oddball stick. I hate having to type-out this stuff all of the time...

YOU DID NOT LISTEN!

Thanks for the answers to my two questions, the education and the constructive critique.

It's not a problem to replace the dual+single I currently have with an actual triple channel kit and use the dual and single other PC's if it is going to improve performance noticably or measureably.

From your experience, what would you actually notice in terms of reduced PC performance and/or actually measure in term of reduced performance benchmarks doing what I did (using a dual channel kit + single on a triple channel board) -vs- what you recommended (using a triple channel kit on a triple channel board)?

^+1 broken record otherwise if I go on... Think of your MOBO like an atomic clock --- keep throwing junk at it -- what time to the 1/1,000,000,000 is it {CAS}? The wrong time is an ERROR to your non-ECC data.

Thanks. I'm trying to not only understand that it matters (you've indicated it does, thanks) and why it matters in technical terms (you've described that, thanks), but also how much it matters (in terms of noticable & measured performance and also longevity of the PC & components)...I'll keep looking for some help with that one - tools to measure what kind of impact there is on performance and longevity.

Very good point about "if you spent the money to acquire quality hardware then why not use it to the best of its abilities.?"...you're right.

I appreciate you guys taking the time to share in forums like this, especially when it's sharing your know-how and experience with beginners/novices like myself.