Btw I meant to ask, whats the -11 & -12 SMP switches about? :$
Mr. Pedantic
Wow! 2-3k drop from web browsing? that's quite a bit!, maybe that explains my flutuations in output?.....
-11 and -12 is how many threads the SMP-application should start, and therefore how many cpu-cores you'll use.
Since a i7-980x has 6 "real" cores and 6 HT-cores for a total of 12, it shouldn't normally be neccessary to use the -12 -switch. But, if you wants to use less than all 12 real & virtual cores, you'll need to use the switch.
Various reports has it that any slow-down of FAH-SMP on a single core can mean all the other cores must wait for this single core, meaning it can have a huge impact on the total production. If you leave a core "free" for gpu, browsing and so on, you won't get these slow-downs. Now, the slow-down is probably not linear, but still it can apparently be substantial.
BTW, if the slow-down is linear, you could get something like:
12 cores, all running 100%: let's say 12000 points/day (to make the numbers very easy to follow).
11 cores, all running 100%: 11000 points/day.
Run with 12 cores, uses 5% of a single core: All 12 cores performs at 95% => 11400 points/day.
Run with 12 cores, uses 9% of a single core: 10920 points/day.
Run with 11 cores, uses 100% of a single core: 11000 points/day.
10% of a single core is less than 1% of computer on a 12-way system, so it's doubtful this will show-up in Task manager at all under cpu-usage...
So, in theory using 10% of a core should only decrease production from 12000 points/day to 11900 points/day, but in practice the performance-hit is apparently larger than this...