4x8gb HyperX Predator 4000mhz OC issue

[KeirML]

Hi there so I'm having an issue with getting 4x 8GB HyperX Predator 4000mhz sticks to run at 4000mhz together.

Motherboard: MSI X470 Gaming Plus Max
CPU: Ryzen 7 3800X

So I started off with 2 individual HyperX Predator sticks that have ever so slightly different models: HX440C19PB3A/8 and HX440C19PB4A/8 (the "/8" just means it's 8gb) and I was able to run those at 4000mhz together no problem. Then I bought 2 more which actually came as a pair both with the model HX440C19PB4AK2/16 (the "K2/16" means kit of 2 16gb).

I so even though 3 of the sticks are HX440C19PB4A and 1 is HX440C19PB3A, they all work fine in a single pair at 4000mhz but when all 4 of them are in they can barely even run at 3200mhz.

Any advice or suggestions?
Am I doing anything wrong?

Thank you

 

[Joxeon]

The sweetspot for ram on ryzen 3000 is 3600~3800mhz with a 1-1-1 ratio between fclk mclk and uclk or else you incur a 10ns latency penalty which means running the ram at 4000mhz would actually make it perform slower than say 3600.

Running 4 dimms is harder on the memory controller than 2 so this means you won't get the same speed with 4 dimms that would with just 2 like you have found. You might be able to get them all running at 3600 by playing around with the SoC and VDDG voltages or the proc-ODT but that will likely be the limit.