Haswell vcore 1.76 volts ? ?

[JackBN]

Just assembled a new system:

ASRock Z87 Extreme 4
i7-4770K
Cooler Master Hyper 212 EVO
The rest irrelevant now.
Did not see the BIOS/UEFI version, whatever came as delivered.

QUESTION:
First thing I did was go to the BIOS/UEFI to look at system health
CPU temp was unremarkable (forgot, but between 30 & 40, as I recall)
*** vcore 1.76 volts ***

As soon as I saw that vcore, I shut down.
Is that voltage correct? Is it safe? What gives?

 

[notty22]

I believe that is the voltage that is supplied to the cpu's voltage rail, first input. Then then internal rails are adjusted for actual core/ mem controller etc.

The other big part of the Haswell power story is what Intel is calling FIVR: Haswell’s Fully Integrated Voltage Regulator. Through a combination of on-die and on-package circuitry (mostly inductors on-package), Haswell assumes responsibility of distributing voltages to individual blocks and controllers (e.g. PCIe controller, memory controller, processor graphics, etc...). With FIVR, it’s easy to implement tons of voltage rails - which is why Intel doubled the number of internal voltage rails. With more independent voltage rails, there’s more fine grained control over the power delivered to various blocks of Haswell.
Thanks to a relatively high input voltage (on the order of 1.8V), it’s possible to generate quite a bit of current on-package and efficiently distribute power to all areas of the chip. Voltage ramps are 5 - 10x quicker with FIVR than with a traditional on-board voltage regulator implementation.

http://www.anandtech.com/show/7003/the-haswell-review-intel-core-i74770k-i54560k-tested/2

 

[VirtualLarry]

Yes, that's the input voltage to the FIVR. Should be around 1.8v.

 

[notty22]

I don't have one to play with. But which voltage showed that high value
as posted above me. The input voltage?

 

[JackBN]

Under Hardware Monitor:
Vcore +1.76
+12.00V 12.144
+ 5.00V 5.064
+ 3.30V 3.344

UEFI Version 1.30

 

[WhoBeDaPlaya]

No worries OP, that's just the input voltage to the FIVR, although if you look at Haswell ES tests, they took 2+V without a hitch.

 

[JackBN]

Thanks guys. Now I can begin a software build without worry.

 

[ArchAngel777]

I am chuckling because I noticed the exact same thing... Henced, I googled it and found this thread. Just bumping to say thanks.