Question xmp ram cause system instabilty

[dragon25432]

Hey
i had 2x8 crucial balistix 3000mhz cl 17
and i had them working just fine on xmp at 2933 mhz
then i bought another 2x8 crucial 3000mhz cl15
and it only worked at 2400mhz
and i later knew that those 2 sets of ram cant work togather
now when i remove one of these 2 sets
it fail to work at 2933 and it cause system instability ( pc become super slow and fps goes down to 80%)
tried to update my bios
same issue , they work fine at 2400 but not 2933
now all i want to do is to go back to my old 2933

and i will sell one of these sets , which one should i keep

 

[Lutfij]

What is the make and model of your motherboard? Which BIOS version are you on for your motherboard?

tried to update my bios
Did you clear CMOS after you'd verified that the BIOS was updated successfully? You try using laxed timings on the rams?

 

[dragon25432]

What is the make and model of your motherboard? Which BIOS version are you on for your motherboard?

tried to update my bios
Did you clear CMOS after you'd verified that the BIOS was updated successfully? You try using laxed timings on the rams?

i have msi b450 tomahawk mobo bios version is 7C02v1J1(Beta version)
i dont know what CMOS is so , no i didnt
and i dont know what u mean by laxed timing on the ram , if u mean i try to 4x8 on those rams i previosly mention so yes i tried that and i still got 2400 mhz

 

[thestryker]

What CPU do you have?

Running 4 sticks is never going to be able to meet the performance of 2 no matter what on a dual channel system.

As long as you're putting a matched pair into the A2/B2 memory slots it shouldn't really be any different than before. It is possible, though unlikely, that your CPU isn't dealing with the lower latency from the newer kit. I would suggest turning on XMP and then manually changing speed to 2933 so see if that gets stability back to where it was previously.