DDR4 overclocking, 2 separate kits

debugSchool · November 28, 2017

So I was under the impression that adding in new RAM sticks, as long as they are identical, would be fine. But after many painful days of figuring out why my system wasn't stable and I couldn't hit the XMP frequency I learned that no eventhough the RAM kits are identical their internal secondary timings could vary wildly.

I'm looking for help as my RAM is supposed to be able to hit 2666MHz but I can't clock it higher than 2200MHz otherwise the system wouldn't boot or one set of the RAM sticks wouldn't be recognised, leaving me with 16GB (half of the capacity) instead.

I'm posting the timing in below as I took them with my phone.

Any help is greatly appreciated

debugSchool · November 28, 2017

As can be seen, the only timing difference is one of the kits have its tRFC at 278 while the other has it at 374. I tried to increase the timing to match 374 and higher but that would simply make only the 278 kit visible, the 374 wouldn't even appear on BIOS. I also tried to bump the voltage to 1.35v and increased the CAS timing from 16 to 17 and 18 but they wouldn't boot at all.

Here's my memory kit if it helps http://www.corsair.com/en-eu/vengeance-lpx-16gb-2x8gb-ddr4-dram-2666mhz-c16-memory-kit-red-cmk16gx4m2a2666c16r

The other photo is uploaded on Imgur instead because it always failed to process when uploaded to the forum https://imgur.com/a/EQ0ny

Edited November 28, 2017 by debugSchool
Image failed to process -200 only on this one image