What I am doing wrong?

[always me]

Sapphire R9 270X Dual-X 2GB GDDR5
AMD FX Series FX-6300 3.5Ghz 6X
G.Skill Ripjaws X DDR3 1600 PC3-12800 8GB 2x4GB CL9

Hi, I know my pc it's not in the high end nowadays but i though it was enough to emulate properly ps2.
I tried every posible combination of settings and speed hacks and the most i get is 20-50 fps in Xenosaga I, 30-50 fps in Dragon Quest VIII, both of them with slowdowns and basically unplayable. Note: even if I play native or 1080p is the same speed, not better or worse, the same
Once I put the original Kingdom Hearts disc on my pc dvd drive and it was running smooth 60 fps 1080p with everything maxed.
Is the dvd speed improvement a real thing?
It's my pc just not powerfull enough or what?
Thanks for you time.

[jesalvein]

If you overclock above 4.0ghz, I guess you can grab a few more fps (maybe up to 40-45 fps)
Apart from that, playing your games on your ps2 is probably your beat bet if you want full fps. Sorry