Always opens files in Camera Raw and takes for ever.

I have made progress since writing the above but still have not solved my problem.
From the beginning I noticed that Photoshop seemed to be using only one core (out of 12) of the processor but then I discovered that when I started to load a raw file into PS Windows Explorer would start running and placing a significant load on the rest of the cores. I also discovered that Windows Error Reporting was running at a high rate with its power usage described as ‘high’. Eventually I tracked down Intel TBMT (Turbo Boost Max Technology) as being the source of the pat of my problem. With TBMT turned off the CPU uses all cores and Windows Explorer does not run wild. But even so PS is still slow. Even when it loads an image the action of ACR sliders is slow and and sticky, and the use of ACR is nowhere near as easy as it is working on the same file with Lightroom. My basic problem remains that PS always opens files in ACR and takes forever to become useable.

This only a recent problem. It does not lie in ACR which runs prefectly well in Lightroom. It has something to do with TBMT but the problem is specific to PS. There is probably nothing I can do about it until either Adobe of Microsoft come up with a fix.