I am having the same issues on a windows 10 I9-9900 with 32GB ram and SSD boot drive. Very frustrating. It makes Camera RAW essentially unusable. Instead of opeing raw files from PS I have to use develop module in LR and then open in PS from there by passing the camera raw in PS.
Did you mean sRGB IEC1966-2.1 which is already selected in Photoshop 'color settings'?
Increasing RAM usage for PS on my 8gb machine from default 60% to 80% has made a marginal difference, but Camera Raw remains pretty much unusable compared to CGRonAdobe's solution - using develop module in LR followed by transport to PS and back.