Precision 3520 memory speed

Hi,

I'm struggling with the memory upgrade on precision 3520, I've done it before many times on different brand machines but this puzzles me.

I got a i5 p3520 that had 8gb memory 

I've upgraded it with 32gb memory but it runs only on 2133MHz and I can't find any way of enabling the xmp profile in bios 

Any advice on how to proceed to get it to run at 2400MHz?