My guess is that hypersli uses modified hal.dll (or, probably ntoskrnl too).As Win 8.1 may need special tweaks including ACPI patches etc, hypersli may break that.
Should be -30 with the load like that (knowing my ss unit). -40 when idle. I control temps only with hot chips that may de-frost evaporator in order to shut down just before it happens.
1.78v here. Cpu is happy with 1.6v @3.55ghz and voltage curve goes to sky after that. I also wasn't able to validate this cpu above 3.65ghz this time - no matter voltage. I'm going to check some other things later this month (vdda and ldt voltages).