xmp XMP problems

[mrawdelirious]

First off, i'm new here, so apologies in advance for any and all potential screw ups.

 

about a month ago, i put together a new Skylake build. this is the spec sheet:

MBO: MSI Z170A Krait gaming

CPU: Intel I7 6700 (cooled by the Coolermaster Hyper 212 EVO)

GPU: Sapphire R9 390 NITRO

RAM: 16GB Corsair Vengeance DDR4 2666Mhz

PSU: Corsair RM 750i

... and a couple of Samsung 840 EVO SSDs all packed together in the H440 Razer edition from NZXT, with some green sleeved cables from Cable Mod and some LED strips from IceModz.

 

then last week, i saw some RAM on sale, really really cheap, and said what the hell. went out and got me another 16GB of Vengeance RAM. The only, and i really mean the ONLY difference between this RAM and the one i already had in my machine, was that this latter one came in a double pack box, meaning that the RAM sticks weren't packed each separately in their own respective boxes, like the ones i got in the machine already, but the two 8GB sticks were bundled in the same box. It is essentially the exact same RAM just packaged differently. I did notice that the numbers on the boxes between the first and the new RAM sticks were also different. The older: CMK8GX4M1A2666C16 (separate 8GB sticks), the new CMK16GX4M2A2666C16 (two sticks in the same box)

 

Started up the PC and got a message that the current memory profile (ie XMP) could not be loaded and redirected me to the BIOS where i had to turn the XMP profile off, dropping the Mhz to 2133 instead of 2666 and then it started windows normally. Before, obviously, with only the frs two 8GB sticks, the XMP was working fine, everything running smoothly at 2666 Mhz.

 

now, my question is could it really be that simply because of the different packaging and the difference in the product numbers, the PC recognizes them as incompatible and refuses to load the XMP, or is there another dark force at work here. I know that you should definitely avoid buying different model RAM sticks, but as i said, these are the same sticks, only packaged differently.

 

thanks guys!

 

 

[blu4]

Are all the RAM sticks rated for the same speed? I think XMP isn't working in this case because those are two separate kits.

[mrawdelirious]

same speed, yes, 2666 MHz.

 

[mrawdelirious]

i put two of these in first http://www.corsair.com/en/vengeance-lpx-8gb-1x8gb-ddr4-dram-2666mhz-c16-memory-kit-black-cmk8gx4m1a2666c16

so, that is each stick packed separately

 

and then i put two of these http://www.corsair.com/en/vengeance-lpx-16gb-2x8gb-ddr4-dram-2666mhz-c16-memory-kit-black-cmk16gx4m2a2666c16

the same RAM, only this one comes two sticks in a set

[MageTank]

You may need to manually enter the speeds. Just change ram speed to 2666, and your primary timings to 16-18-18-35, and VDIMM to 1.2 This should allow both sets to work together.

 

Just a side note: this XMP profile is pretty terrible. 2666 CL16 is not great by any means. You would be able to do much better manually overclocking, but that would take a lot of time.

[mrawdelirious]

right... i'm not much of an overclocker anyway... but since the XMP is fairly simple to enable in BIOS, why not.

 

thanks!

[mrawdelirious]

perhaps any other ideas anyone?