Ed Light wrote:
> Thanks, Paul.
>
> I did notice exactly that droop during Intel Burn Test. It was
> intermittent.
>
> This board lets you set Vcore to specific voltages, from tiny to
> massive. I don't see anything else there.
>
> With EIST and C1E disabled, shouldn't the voltage increase endure into
> Windows? Or is there something in Windows that could reduce the voltage?
>
OK, I tried a few experiments here.
First, I used RMClock, to get the particulars for my processor.
E8400 333*9=3000MHz, FSB1333 (333*4), low multiplier gives 2000MHz.
6X 1.1000 V
9X 1.2625 V
CPU-World says that processor can span 0.85-1.3625, but it looks
like Intel has it limited as shown in RMClock.
So first, I tried with no boost. The assumption is (since I'm running
with EIST and C1E disabled anyway), that the VID register is already
pegged at 1.2625 volts. And the Vcore chart in RMClock has that
value printed on it as well.
Applied Measured Speedfan
CPUZ
1.2625V 1.224V Idle 1.22 etc
1.216V Load
I won't show any more Speedfan, because the rounding to two digits is
kinda a waste of time. Note that there is hardly any change under
load, and I've only got a 65W dual core installed. The measured voltage
value is "on the low side" by 0.0385V .
Now, I apply some boost. Any value set in the BIOS, higher than 1.2625
for this particular processor, would require boost applied somehow.
So a second register must have a boost value entered in it.
Some of the Asus boost circuits in the past have been pretty sloppy,
but this one seems pretty good.
Applied Measured
CPUZ
1.3250V 1.280V Idle
1.272V Load
In this case, it is on the low side by 0.045V.
Applied Measured
CPUZ
1.3625V 1.320V Idle
1.312V Load
In this case, the measured value is low by 0.0425V.
And in each case, RMClock still thinks the register is
set to 1.2625V. So the extra voltage is not a result
of the CPU register setting for the VID pins, but is
determined by whatever is used to add a boost.
RMClock says 1.10000V is the lowest register value I
can use. CPU-World claims the E8400 ranges from 0.85V
and upwards. The Asus BIOS won't allow that value to
be dialed below 1.10000V . Which means there is no
"undervolting" capability on my board, only boost.
And the boost is used, whenever voltages above the
range limit in the CPU, are asked for.
Since CPUZ seems to be reading the measured voltage,
if you turn on boost in your BIOS, you should be
seeing the effects. In fact, you should be able to
measure them in the hardware monitor BIOS page, after
doing a Save and Exit with the new Vcore voltage dialed
into the BIOS. So if the value stubbornly won't change,
when you know it is above the max value listed in
RMClock, then your boost is either non-existent,
the BIOS is wrong for the board (i.e. it's loading
the wrong GPIO bits to set the boost voltage),
or something along those lines. The BIOS setup screen
doesn't have to match reality, as I've had boards
where the memory timings shown in the BIOS, are not
actually being loaded into the hardware. So the
BIOS setup is not necessarily "correct" in all cases.
It is one of the reasons, I rely on CPUZ to verify
my RAM timings, rather than believe what I'm seeing
in the BIOS.
You can get RMClock 2.35 here. That will allow you to
verify the "range limited" value of your CPU VID register.
http://cpu.rightmark.org/download.shtml
Does EasyTune allow the voltage to be modified while
the system is running ? Or does it only monitor ?
Maybe you can see if EasyTune knows how to change it.
And that indeed might require a driver. You need
the equivalent of "GiveIO" or the other mechanism
is the BIOS passes an ACPI object to the OS, and the
driver uses that to make the changes. On an Asus
motherboard, that would be something like a System
Device called "ATK0110 ACPI Utility". That is a pseudo-device
passed by the BIOS to the OS. I don't know what
the equivalent would be for a Gigabyte motherboard.
You could try Device Manager, or Lavalys Everest, and
see if there is a strange "System Device" present.
Right now, mine seems to be using a Windows driver
of some sort. I don't think I have any utility here
loaded right now, to access ATK0110 and test it.
(It might be AI Booster, but I'm not installing that
kind of crap on my system :-) When I overclock, I use
the BIOS, as bad as it is.)
Paul