(New edits to all my thread comments here) Between BF3 and BF4, the same basic version of Frostbite was being used for those games. For this game, Frostbite has been incrementally advanced, and Hardline requires more hardware power (although apparently to quite the extent I've had in mind). Beta copies, unlike Demo copies, are not supposed to be particularly predictive of anything influencing game performance, sorry.
The BF HL specs:
Minimum:
OS: WINDOWS VISTA SP2 64-BIT (with KB971512 Update)
PROCESSOR: Athlon II/Phenom II 2.8 GHz, Intel Core {Quad?} i3/i5 2.4GHz (struck out the parenthetic)
MEMORY: 4 GB RAM
GRAPHICS CARD: ATI Radeon HD 5770 (1 GB), NVIDIA GeForce GTS 450(?)
HARD DRIVE: 60 GB
DIRECTX 11
I have edited the Geforce minimum because the official version contains a typographical error that EA seems reluctant to correct. However, I'll have to track down a newer copy, in which cores were referenced, I'd thought (turns out not to be the case, sorry).