Mobo brand voltage differences for same cpu

[skaughtz]

I have two 3570k systems.  One on an ASRock Z75 Pro4 and one on an Asus P8Z77-V LX.  Both are running at 4.2GHz with a -0.02 voltage offset.  But I just noticed that both are reading quite different voltages.

 

TheASRock board gives me readings of:

0.960V VCore in the bios

0.816V VCore/0.856V VID idle

1.072V VCore/1.196V VID under 100% load

 

The Asus board gives me readings of:

1.048V VCore in the bios

1.016V VCore/1.076V VID idle

1.192V VCore/1.224V VID under 100% load

 

Those are differences of 

0.088V in the bios

0.2V VCore/0.22V VID idle

0.12V VCore/0.028V VID under 100% load

 

In all cases the Asus board is recording higher voltages (the idle and load readings we're through HWMonitor, CPU-Z, and Core Temp).

 

So before I go through the bother of testing each CPU on the opposite board, I thought I would check here.  Is this simply a case of Asus engineers designing their board to pump out more voltage than the ASRock, or does the CPU on the Asus board require that much more juice to function at the same clock and same negative offset?  Maybe both?

 

 

 

 

 

 

[Guest]

So the Asus board is 4+2 VRM vs the AsRock 4+1 and we are displaying minor differences in voltage readings here, within a small ball park.

 

The question being Asus pumping more voltage, may be a true statement while 2 different people wrote 2 different bios's. I don't see this to be an issue while Both CPUs sound to be operational, but further testing for stability and temps I assume is your testing path.

 

It would be interesting to see which board could use the least amount of voltage at X overclock. 

 

Good stuff. 

[skaughtz]

1 hour ago, ShrimpBrime said:

So the Asus board is 4+2 VRM vs the AsRock 4+1 and we are displaying minor differences in voltage readings here, within a small ball park.

 

The question being Asus pumping more voltage, may be a true statement while 2 different people wrote 2 different bios's. I don't see this to be an issue while Both CPUs sound to be operational, but further testing for stability and temps I assume is your testing path.

 

It would be interesting to see which board could use the least amount of voltage at X overclock. 

 

Good stuff. 

So I decided to screw around a bit more with the voltages.  I managed to get the ASRock board to go to 4.5GHz with a +0.08V offset (+0.1V increase total).  With those setting that system managed to stay stable under 10 minutes or so of Prime 95 before I ended the test.  The same settings on the Asus board caused a hang and crash on the Windows welcome screen and I didn't bother to try any further.  That much more voltage certainly isn't worth the extra clock speed.

 

I guess that means that that the cpu on the Asus board is just a worse chip than the other.  It still doesn't necessarily explain the boards providing what are essentially different stock voltages, if the bios readings are to be believed at least.

[Guest]

34 minutes ago, skaughtz said:

So I decided to screw around a bit more with the voltages.  I managed to get the ASRock board to go to 4.5GHz with a +0.08V offset (+0.1V increase total).  With those setting that system managed to stay stable under 10 minutes or so of Prime 95 before I ended the test.  The same settings on the Asus board caused a hang and crash on the Windows welcome screen and I didn't bother to try any further.  That much more voltage certainly isn't worth the extra clock speed.

 

I guess that means that that the cpu on the Asus board is just a worse chip than the other.  It still doesn't necessarily explain the boards providing what are essentially different stock voltages, if the bios readings are to be believed at least.

You could always swap CPUs and see what happens.