Same part number different RAM

[stevethegil]

Got bargain on QX9770 socket 775 CPU, had a big case on hand.
Bought Asus Maximus Extreme so play with overclocking
Assembled with plenty big power supply, water cooling, crossfire graphics

I made an assumption that 2 kits of Gskill Ripjaw X F3-128000CL9D-4GBXL would be very similar with todays manufacturing techniques and if I bought at the same time I would get sets manufactured at the same time, WRONG.

I put them in without even noticing the differences they memtested fine for 12+ hours. I was experiencing, even at standard timings @ 2T, instability in POST and intermittent hard hangs when working. I found on inspection:
One set green PCB manufactured Feb 2012 (slot 1 in image below)
One set black PCB manufactured Jul 2011 (slot 2 in image below)
I did not think they would be that different to cause the trouble?

What is very surprising to me is that they have different XMP values in the SPD's. Why the difference, 1T and 2T would have to make them incompatable if running XMP and indeed make them different RAM? I thought all SPD values were programmed to the chips in manufacture and would stay the specification for that Part No?

[Tradesman]

Not sure where you got them, but odd anyone would have two sets that far apart, anyway, for info, any time you mix sets it can be problematic, I know I've bought a number of the same sets at once from the Egg, here in the states, and generally they have sticks in numeric sequence (i.e. set 1 might have serial #s 1-4, the second set might be 5-8, then 9-12, etc.) but regardless, two of the sets might play together or might not. Anyway, in this case I'm guessing you got two sets with slightly different SPD programming the early one is prob the original which was centric to the 1155 (P67, Z68, H67 chipsets (Sandy Bridge)) and the second might be upgraded programming to also accomodate the 1155 with the Z77 chipset (Ivy Bridge CPUs). As they are 1600 sets, think they should pay together, though not under XMP as the programming for XMP is by the set, there are different requirement, especially in the advanced timings for 2 stick setups and 4 stick setups, I'd suggest clearing CMOS, set the DRAM to Auto or manual instead of XMP, CR (Command Rate) to 2T, DRAM voltage to 1.55, and may need to raise the MC (Memory Controller) voltage (believe NB or North Bridge on your mobo), prob + .1 or a little more. Give it a shot and let us know

[stevethegil]

The RAM was bought new from a Ebay seller that I do intend contacting.

You may be right in tuning for chipset theory. I would say if it is the case just give the RAM a different name as it is for a different purpose and there are a million different names you could use.

As for the suggestion on setup I will get RAM that will play together. Right now I have just the green PCB set in and PC runs fine. I don't know what seller will say it is some time since I bought. With the demands in my life and the complexity of build it took a long time to come together. He can ignore me, he can say anything he likes as I have nothing to hold over him anymore.

[stevethegil]

Just a thought you could have Ripjaw Xandy and Ripjaw Xivy and then you would not confuse the two and try to mix them.

[Tradesman]

Either works fine on either platform, it's really basically the same as the BIOS on motherboards, though not near as often as a bIOS, as more is learned the SPD programming can be fine tuned to optimize performance, and DRAM isn't really oriented to adding a second set. XMP is programmed to the sticks by set, i.e. a two stick set might take a tRFC of 128 while with four sticks it might need 188. That's also why DRAM is offered in 1, 2, 3, 4, 6 and 8 sticks sets ranging from 1,2, 3, 4, 6, 8, 12, 16, 24, 32, and 64 GB sets. These days with the higher freqs and densities DRAM is much touchier and also while each set is tested, to ensure the sticks play together. As I mentioned, I would guess the sticks should play together fine or with minimal adjustments, I've often upgraded systems for clients with even different DRAM and generally always get them to play nice (though it can be frustrating at times). As far as the suggestion for name changes, could send it through to GSkill (I'm not GSkill) or if you want I can drop them a note.