This is normal for old orbus; if this was during a reborn beta test then it would be weird; While I do not have a spec sheet on me a have 4.8 (overclocked from 4.0) ghz cpu with about around 16-20 gigs of ram on a 1070 graphics card with steamvr super sampling down to 80% from 100% and I get unstable 90 in highsteppe and 20 fps in raids.
This is due to the assets in the current game not being optimized for vr, having to not only render other people, but their hand movements, projectiles, and also the enemies that it causes the game to slow. Reborn uses assets made for vr by the devs and I recommend seeing if you have 90 fps in the beta this weekend.