My crunching colleague suggested to me that I take a different approach, somewhat similar to something I saw here, maybe not in this thread, but in this or another thread. He said I should try reducing the number of cores used, and set them at 100% usage. He said that I would see an immediate smoothing out of CPU usage in my Processes meter. Boy was he ever right. Instead of very wide fluctuations, I saw that the CPU usage was quite smooth with a minimum of fluctuation.

Unfortunately, this did not work to reduce temperatures on most of my machines. In fact on those machines where I basically swapped the percentages and used less cores but at 100% usage, the temperatures rose up to just under the limits for the various processors. Only on the machine with the i7-3930k was this satisfactory. Using 10 threads, at 100% usage, I have temperature readings all around 70 deg C, the limit being 91 deg C. So, that's fine.

Bad temperatures drives me nuts. The other processors, all with limits around 100 deg C, were running in the 70-75 deg C range prior to the move, and in the very high 88-95 deg C range after the move.So, I switched all of those machines back to 100% of the processors at a reduced level of usage. I got my temperatures back where I had them and where I wanted them, about 20% below their limits.

I still believe that this question of heat with the very fancy new processors is an issue to deal with in how we set up BOINC to run.

There's the TThrottle application, which I don't like but many WCG members happily use to keep temperatures in check. There you can set your desired max CPU temp and the program throttles BOINC as needed.

So, I finally got a reply that was very specific and very useful. I had posted this same question at the BOINC forums. The silence was deafening. But some prodding got a reply, from someone whose skills I higly respect:

"What type of heatsinks are you using on your CPUs? The i7-920 runs hot because of the 130 watt TPD. If you're using the stock heatsinks running @ 100% is a very bad idea. I have no experience with the 3930K but I would not run that @ 100% with the stock heatsink either. I do have several 2600k CPUs that are air cooled with aftermarket coolers and they run 24/7 without issues. AFAIK there are no settings in BOINC to adjust the GPU settings. For that you'll need a third party tool like MSI afterburner."

So, the other shoe is dropped on the i7-920. And, I believe it goes also to the rest of my processors, the i7-920 being at this point the most primitive.

All of my processors have their normal stock heatsinks. So, all of my BOINC settings for CPU usage, the number of cores and the percent of usage, are reduced from the maximums. All of my temperatures are about 20% below the maximums. I am getting plenty of work done.

I conclude that it is of paramount importance to put a temperature gauge on each computer and pay attention to it. The decision of what is the best combinations of numbers of cores and percentage of usage can differ from processor to processor, so some testing needs to be done to determine what is best in each case.

For me, the issue is resolved.