So I finally bit the bullet and upgraded to Windows 10 Pro 64 from Win7x64 (partly to fix RX7 which wasn't working) and now I have lots of clicks and pops when I playback anything in Cubase with my previous settings. Oddly, Ableton Live 10 and Cakewalk don't have this issue after the upgrade, although I detected one or two clicks in a large Reason project.
At first it was quite bad. Even with a completely empty project loaded and not playing the real time peak meter was averaging about 50 percent and was spiking pretty frequently. So I did a little searching here and found a few suggestions. I disabled every Windows service that I knew wasn't necessary and got my load down to 1.6 Gb RAM (with Cubase closed). That helped some but not enough. Then I saw the suggestion to change the Processing Precision from 64 bit to 32 bit. That helped quite a bit more and now I can play a 3 minute piece and only hear 3 or 4 clicks during the whole playback, but I heard none before upgrading and this is the same project with the same hardware, just the OS upgrade.

I have Steinberg Audio Power scheme enabled, and ASIO Guard set to Normal. Under Windows 7, I was able to play back projects at 64 samples, now I have to increase that to 256 to get clean playback.

Anything thing I'm missing? Any help would be appreciated. System specs in my signature.
Thanks.