Thanks DAV. Maybe I'll upgrade.
It is clearly an issue with how many windows are NOT minimized. Even if they are not visible (i.e.-behind each other), if they are not minimized, they increase the load. My solution is to flip through my charts as I need them. So everything is minimized except for 2 multicharts (each with 4 subcharts). This places a minimal load and the system works well. Frankly with two 20" monitors filled with the 2 multicharts (i.e.-8 individual charts, 2x4), I can't see more anyway. Then I just bring up other windows as I need but make certain to minimize them when not being viewed. I have a total of 21 TWS windows created, 14 of which are the multicharts (with 4 charts each) and I experience no slowdown.....unless more than 2 or 3 chart windows are not minimized.
The only problem I see is if I were to expand to say 3 or 4 monitors, then the CPU load, in theory, would be way too high. But that's not the situation, so no worries now!
I'll try build 899 and see what happens. Again, by minimizing windows not being viewed, instead of leaving them "up in the background", the system works fine but it's inconvenient at times too have to remember to minimize the window(s).