Dell 5510 DE single core is nearly 4 times slower then on a three year old laptop when running sysbench

Hi,

My Dell 5510 DE takes 93 seconds to run compared to 24 second on a 3 year old 4600U based laptop.

sysbench --test=cpu --cpu-max-prime=20000 run

I'm running kernel 4.4.0-78, BIOS 1.20, disabled Intel SpeedStep in the BIOS just in case.

I have noticed that the CPU speed is 800000 and scaling governor was powersave even when the device was connected to a Dell 130W 6.67A power adapter.

Help!

Update: Upgraded to BIOS 1.2.25 and tested with Live Ubuntu. Still no luck!