Why CPU over temperature with two additional RAM sticks?

Hello everyone,

My brother got two new RAM sticks for his birthday.

2 x 8GB DDR4 3200 MHz, CL21.

the old 2 bars were

2 x 8GB DDR4 3200 MHz, CL22.

After endless back and forth, it finally worked with the four bars after a BIOS update.

But now my brother gets the message cpu over temperature when he starts up.

The message only appears when all four modules are connected. Is the CPU trying to overclock automatically due to the different CL values, and is that why it's getting hot? All RAM settings in the BIOS are set to Auto. In addition to the additional RAM, we also installed two front fans and an HDD.

This surprises me, since I also have two sticks with different CL values, and everything works perfectly. I just thought the faster sticks would adjust to the slower ones. But I don't really have a good grasp of RAM…

If you have any ideas I would be very grateful.

If that doesn't work, I'll probably need 2x 16 GB sticks.

MB: ASUS PRIME B550-Plus

CPU: AMD AM4 Ryzen 7 3800X

CPU fan: CPK AMD cooler Xilence Performance A250 PWM cooler 92mm 95W

GPU: VGP AMD Radeon RX 6700 XT 12GB

Kind regards

griseo03