Ares b die overclocking low write speed

[DaZzZa]

Hi
I've recently moved from an old 3930k to a ryzen 5700x and wow are the bios different lol.

I have 4x8gb 3200 g.skill ares which have b-dies and I've cuffed the settings to get them at 3600 with 14 14 14 28 1cr with 1.4v but I must be missing something as the write speed is way off the read speed 47gbs read vs 27gbs write, I expected write to be a little lower but not 20gbs?

MSI X570 tomahawk board

Anyone point me in the right direction please
cheers

 

[exa]

On single ccd chips the write is 32byte per cycle, and read is 16byte per cycle. So in tests like aida64 cache and mem bench your write bandwidth would be around half of your read