Buying two identical sets of ram and combining them

Jaden Callaway

Honorable
Sep 26, 2013
7
0
10,510
Hello all, have a quick question that I have not been able to find a clear and concise answer on. I currently own THIS ram, I have now decided that my demands are too great and want to buy an identical set and combine them. Someone told me that there is a chance the ram will be incompatible with itself and the only way to do that would to be to buy the 4x8gb pack, as combining two different 2x8gb packs may not be 100% compatible. Is there any truth to this? Thanks!
 
Solution
Yes, I have 2 sets of 2 x 4 that are good by them selves but not together(this not good does not stop it from working, but it will toss out an error every few months related to memory). It is extremely rare. They tested fine on another system and seemed to pass memtest, but they are just not 100% stable. Even lowering the speed and timings did not help in my case

I did just say screw it and got a 2 x 8 kit. 16 was more than enough for me.

I would still say you have a rather good chance as that is the ONLY time I have had this issue(1 of those old sets now lives in my media center.).

You could check your motherboard makers QVL for memory to see if those sticks are on the list of 4(some memory is listed for 1 and 2 sticks only for my...
Yes, I have 2 sets of 2 x 4 that are good by them selves but not together(this not good does not stop it from working, but it will toss out an error every few months related to memory). It is extremely rare. They tested fine on another system and seemed to pass memtest, but they are just not 100% stable. Even lowering the speed and timings did not help in my case

I did just say screw it and got a 2 x 8 kit. 16 was more than enough for me.

I would still say you have a rather good chance as that is the ONLY time I have had this issue(1 of those old sets now lives in my media center.).

You could check your motherboard makers QVL for memory to see if those sticks are on the list of 4(some memory is listed for 1 and 2 sticks only for my board).

Whatever you do, please make sure you have something better than Windows 7 Home Premium as it maxes out at 16 gigabytes.
 
Solution
Yes ideally it's a wise if at all possible to buy a matched set...... but even then it doesn't always work....but at least then ya guaranteed an exchange.

I recently added a DDR3-1866 set to a DDR3-1600 set (1600 was no longer available from manufacturer) ....clocked it down to 1600 at same timings and all has been good since. Note that is also about having 4 versus 2 sticks as much as having "same" .... 4 puts a bigger load on memory controller..... as was said above ...reducing timings, reducing speed and increasing voltage are all steps ya can take to improve stability if its a problem.
 

Tradesman1

Legenda in Aeternum
There's a lot of truth to it, mixing set can be problematic, even of the same exact model, and the likelyhood of having problems increases as the freq goes up, that's why DRAM is offered in such a wide variety of number of sticks per package, those sets each have sticks that are tested to work together, and why prices are higher for the larger number of stick sets....Also of note with you, and 2400 sticks, XMP is programmed by the package so it may well cause problems if you try it, i.e. a 2x8 set of DRAM may use a tRFC (one of the many advanced timings) of 220 while the same sticks in a 4 stick config will require a tRFC of 314, other advanced/secondary timings may vary also (though none as extreme as the tRFC). Another thing you can run into, particularly with higher freq sticks is it often takes voltage adjustments to DRAM and MC (memory controller) to get them to play nice, with the higher freq already at 1.65, don't have a lot of wiggle room