**Official DFI LanParty UT 790FX-M2R Review/Overclock/Guide Thread**

[justapost]

EDIT (updated above pic):
That above is lowest voltage for NB/CPU stable too, any lower it freezes.

I'm running near enough exact settings as you Achim, especially CPU settings. My system idles 108W AC @ this:
And with CnQ enabled now in the first pic above, it idles 94W AC (2x HDs, 2x 5V fans). Very good options to access and edit these registers IMHO, don't you think?

Yeah those p-states are great for tweaking, running with one HD and 3xFans atm.

CPU 2.6 (217x12) at 1.3V CPU VID
NB 2.17 (217x10) at 1.3V NB VID
MEM 578MHZ at 2.25V

idle: 157W AC
load: 270W AC

CPU .8 (217x4) at 1V CPU VID
NB 2.17 (217x10) at 1.3V NB VID
MEM 578MHZ at 2.25V

idle: 139W AC
load: 180W AC

Lowest possible consumption is cpu 200x4 at 0.9V nb 200x9 at 0.95V. In idle ~105W AC. So the board still needs more tweaking to beome more efficient.

A note aboute the NB multi. If CnQ is set to Auto in the Bios, the NB multi is always 9x. So it's required to up the ref HT to tune the nb.
However with above scripts it's possible to set the p-states and switch between em manual. Those work with CnQ disabled in bios.
A third p-state would be great, i'd like to have a low normal and high p-state.

Here are my settings I run with those two:

Current: MSR 0xC0010070
0x00000000 0x4800340A (1.100V NB/1.225V CPU)

P0: MSR 0xC0010064
0x800001BC 0x4800340A (1.100V NB/1.225V CPU)

P1: MSR 0xC0010065
0x80000187 0x48007040 (800/1800 0.850V/1.100V)

V above = VID.

As you can see, VIDs is how the processor controls all volts internally even for CPU and NB in all P-States including boot states. So that 1.250VID NB is 1.232V/1.240V. But NB VID never changed in P-State 1 unless you do this manually. I know NB FID cannot be changed after boot and that's why it won't change where HTC is active where GCLK downclocks nor when you have CnQ enabled but ... messing with the NB VID register it works fully, like so:

Is 2.6GHz stable at 1.225V VID?

I can change CPU DID to 1 and 2 real-time but anything higher is no go.
I've not tried NB DID yet.

The predefined p-states differ in the CPU DID and have the same CPU FID, can be it's faster to switch between the modes if only the DID changes.
NB DID must be equal on all cores's and p-states, no way to change the nb speed on the fly.

Yep, power is controlled by the CPU VID, NB VID, IddValue and IddDiv which also sets the TDP and that changes the Tcontrol and Tcontrol max limits apparently.

Have you played with IddValue/IddDiv? I assume it can be used to define under which load the 0 p-state get's used.
Do you know a stress-utility which can generate stress in steps? Maybe sandras energy efficiency test shows a difference.

BTW I know Tcontrol is not the actual temp value in degrees but just an arbitrary value to represent it. That's why it's allowed to read subzero at high ambients.

It's like i expected. calibrated against the worst case temp with arbitrary scaling.
Looking at the MSR registers HTC seems to be an feature of future steppings.

What happened was, my first 9500 which is the main one I experimented highly with temps, it read the temp in BIOS the same as the physical Tcase temp most likely because it was missing the offset, but the ones after that were all different. This 9600BE reads the register properly (sub-ambients).

Same with F3xA4, I asked about it because on the NB register access it read 0b for me so I thought there's another way. It reads correctly now but many times it blanks out or reads F's.

In terms of temps i rely on the external sensor on the mobo. This one reports the highest temps. The avreage is +10° over CPU temp. A probe next to the prozessor reads the same temps as the cpu sensor most of the time, so i assume this temp is actualy higher.

Thanks for adding the bits, makes me not have to read the guide. Although you did make me read up the guide once again you know...

Skimmed over the whole thing one time, just to get an outline and know where to look for what. Alot of extra research is required on my side to read that doc.