I cannot answer that question as I do not do 4K raw and besides there are many different codecs. But I have a suggestion, run my Premiere Pro BenchMark (PPBM) submit the results and I can tell you if your present hardware setup is properly tuned for Premiere Pro.
Can you, certainly!
If what you really want to know is how well will it work, you need to offer up more details regarding:
Which 4k Raw, what bitrate!? (Sony consumer, GH4, RD3, etc.) RED is much more demanding than most other 4k media
Workflow? (real-time color grading, multi-cam, etc.) Straight cuts without any realtime correction is easy compared with more complex timelines
And your personal pain threshold? (scrubbing can stutter, I'm picky about scrubbing, need to playback on 4k monitor at full res. with less than 1% dropped frames, etc.)
And, what are your drive(s) in this system (i.e. Boot drive 512GB Samsung 840 pro boot drive, 2x RAID 0 2TB WD Blue RAID zero for media, projects, etc.)
Or, possibly even better, just do it and see how it goes. You seem to indicate that you already have this workstation.