Getting 2 different sets to work together

[Unrivaledx21]

I realise that this is not recommended. I already have these sets though so what I am wondering is the best way to make them compatible in xmp. Both sets are the exact same model of RAM with one set being purchased roughly 2 years later. I've managed to get the system stable with XMP off, but when using XMP the system gets a BSOD randomly during usage. I realise that XMP would be specific to one set, but is there any specific settings / timings that I can adjust to assure stability with XMP enabled?

 

[mattyfez]

I'd suggest overclocking the ram manually and see how far you get before it becomes unstable.
That's all XMP is really, it's a preset overclock that should work fine with matched sticks but it's not at all guaranteed if you mix and match.

Also is the BSOD code ram related? And not some other random issue?
Also it sounds like you are running 4 sticks (2x2 matched pairs) which could further complicate things if trying to use XMP

 

[Unrivaledx21]

Thanks a lot for your response. I've managed to have success and a noticeable improvement by turning XMP on and increasing the tRFC to 314 and the dram voltage to 1.6. The ram itself is specified 1866mhz 9-10-9 28 at 1.5v. I did try to change the voltage though to 1.55v and had a BSOD within 10 minutes, so have increased it back to 1.6v. I may even attempt to push this ram to 2133mhz at some point, but not sure whether it is worth it if it requires increasing the timings.