I've been chugging along at more than 8M cEMs/sec, but around Jan. 1st my rate went down to around 6 cEMs/sec; I thought one of my machines went offline (judging from the rate decrease), so I rebooted it but the rate continued to plummet. It's now a little less than 5M cEMs/sec.

Looking in Task Manager, it shows two SB processes running, both at 50% (this is a dual core). Even if my other machines are offline, my dual core should be crunching at 6-7 M cEMs/sec.

Any ideas what's going on here?