Question Installing a 2nd pair of RAM stops PC from posting

Sep 22, 2021
I'm trying to install a 2nd set of RAM (Corsair Vengeance Pro 2x8gb 3000mhz CL15 - CMW16GX4M2C3000C15) which runs at different speeds to the set I have currently installed (Ballistix elite 2x8gb 3600mhz CL16). Every stick works individually and in dual channel separately, but not all 4 together, in any combination. I also can't get 2 + 1 to work.
*Edit: the fans etc do start at full speed, but they stay that way eternally without giving any display

After some research, it seems like the combination of my cpu and mobo may make it quite difficult to set up a RAM mix so it works, but apparently it should be possible. However, I'm not really sure how to go about it.

So far I've tried:
-Running them with xmp enabled
-Running them 2133mhz
-Running them at 3000mhz (lowest kit speed) at highest latency (16-18-18-38)
-Running them at 2133mhz at highest latency
-Running them separately in dual channel (successful)
-Running 1 stick at a time in each slot to check for faulty slots (all working)

Oh, and I've raised the DRAM voltage to 1,4 from 1,35.

I'm aware that I'm crippling my faster kit by trying to make it run with the other kit, but the speed doesn't matter (to an extent)-- I just want the 32gb for faster rendering.
I've decided to ask around before I continue and possibly break something.

My specs:
-Mobo: b450 tomahawk max
-CPU: Ryzen 5 3600
-GPU: RTX 2060S
-PSU: Seasonic Focus GX550 (80+Gold)