GA-P55M-UD4 and G.Skill F3-16000CL9D-4GBTD recommended settings

[EFS_Junior]

CPU Clock Ratio 20X << BCLK = 200MHz "appears" to be the limit for the MB @ 19X, 20X, or 21X (even BCLK = 201MHz fails)
Advanced Core Features [Press Enter]:
Intel(R) Turbo Boost Tech................[Disabled]
CPU Cores Enabled........................[All]
CPU Multi-Threading......................[Enabled]
CPU Enhanced Halt (C1E)..................[Disabled]
C3/C6/C7 State Support...................[Auto]
CPU Thermal Monitor......................[Auto]
CPU EIST Function........................[Disabled]
Bi-Directional PROCHOT...................[Auto]
QPI Clock Ratio..........................[x32]
QPI Link Speed...........................[6.4GHz]
Uncore Clock Ratio.......................18x << My bad, this is NOT user selectable
Uncore Frequency.........................3600MHz
>>>>> Standard Clock Control <<<<<
Base Clock (BCLK) Control................[Enabled]
BCLK Frequency ..........................[200]
Extreme Memory Profile (X.M.P.)..........[Disabled]
System Memory Multiplier (SPD)...........[8.0]
Memory Frequency (MHz)...................1600
PCI Express Frequency (MHz)..............[100]
C.I.A.2..................................[Disabled]
>>>>> Advanced Clock Control <<<<<
CPU Clock Drive..........................[ 800mV]
PCI Express Clock Drive..................[ 900mV]
CPU Clock Skew...........................[ 0ps]
Advanced Memory Settings:
Extreme Memory Profile (X.M.P.)..........[Disabled]
System Memory Multiplier (SPD)...........[8.0]
Memory Frequency (MHz)...................1600
Performance Enhance (SPD)................[Standard]
DRAM Timing Selectable (SPD).............[Expert]
Profile DDR Voltage .....................1.5V
Profile QPI Voltage .....................1.1V
Channel Interleaving.....................[Auto]
Rank Interleaving........................[Auto]
>>>>> Channel A & B
Channel A Timing Settings [Press Enter]:
Cas Latency Time........................[9]
tRCD....................................[9]
tRP.....................................[9]
tRAS....................................[24]
>>>>> Advanced Timing Control
tRC....................................[Auto]
tRRD...................................[Auto]
tWTR...................................[Auto]
tWR....................................[Auto]
tWTP...................................[Auto]
tWL....................................[Auto]
tRFC...................................[88]tRTP...................................[Auto]
tFAW...................................[Auto]
Command Rate (CMD).................. 2 [1] << This works, although everything I've seen in the G.Skill forums "suggests" leaving this at 2T
>>>>> Misc Timing Control
B2B Cas Delay..........................[Auto]
Round Trip Latency.....................[Auto]
Channel A Turnaround Settings [Press Enter]:
Different DIMMs........................[Auto]
Different DIMMs........................[Auto]
On The Same Rank.......................[Auto]
>>>>> Channel A Writes Followed By Writes
Different DIMMs........................[Auto]
Different DIMMs........................[Auto]
On The Same Rank.......................[Auto]
Advanced Voltage Settings:
******Mother Board Voltage Control ******
Voltage Types............Normal......Current
--------------------------------------------
>>> CPU
Load Line Calibration..................[Auto]
CPU Vcore..................1.21875v....[1.38750V] << Going too high here and I run out of core temperature headroom and system is unstable in Prime95 at 21X multiplier (4.2GHz) even at 1.45V
QPI/VTT Voltage..........1.100v........[Auto] < I tried 1.23V, 1.21V, 1.15V, and even 1.1V. This setting "appears" to cause the continuous BIOS cycling if set to something other than [Auto] ?????????
>>> MCH/ICH
PCH Core....................1.050v.....[1.120V]
CPU PLL.....................1.800v.....[Auto]
>>> DRAM
DRAM Voltage..............1.500v.......[1.500V] << RAM is spec'ed as 1.500V,
voltages available here are 1.50, 1.56, 1.58, 1.60, 1.62 (DRAM voltage "appears" to set to this when [Auto]), 1.64, 1.66 (pink), ... << Can't set to 1.54V, only choices here are 1.50, 1.56, 1.58, ... , as stated above
DRAM Termination..........0.750v.......[Auto]
Ch-A Data VRef............0.750v.......[Auto]
Ch-A Data VRef............0.750v.......[Auto]
Ch-B Data VRef............0.750v.......[Auto]
Ch-B Data VRef............0.750v.......[Auto]
Miscellaneous Settings:[/SIZE]
Isochronous Support....................[Enabled]
Virtualisation technology..............[Enabled]
USB Controllers .......................[Enabled]
USB Legacy Function ...................[Enabled]
USB Storage Function ..................[Enabled]

Don't have a clus as to what is happening with the QPI/VTT Voltage setting. The OS boots at 21X (4,2GHz) just fine, but core voltage have to be set too high for stability purposes (Prime95), I run out of temperature headroom.

Maybe I'll just have to be satisfied with 4.0GHz?

[Lsdmeasap]

Try using 190x21 then and see how that goes.

QPI/Vtt issue may be your BIOS, try a clear CMOS or update to the latest Beta and see if you can then change it.

4Ghz is much easier to get stable at lower voltages, and not really much different than using 4.2, so it may be the best thing to do since your temps are getting up there.

[EFS_Junior]

Try using 190x21 then and see how that goes.

QPI/Vtt issue may be your BIOS, try a clear CMOS or update to the latest Beta and see if you can then change it.

4Ghz is much easier to get stable at lower voltages, and not really much different than using 4.2, so it may be the best thing to do since your temps are getting up there.

1) OK, 190x21 will give me another data point at ~4GHz.

2) I have the GA-P55M-UD4 MB with F9 BIOS (AFAIK this is the latest and I haven't seen a beta F10x to date).

3) I figured out what was going on in current F9 BIOS settings (via EasyTune6 voltage readouts); Memory get's set to 1.62V [Auto] and QPI/VTT Voltage get's set to 1.41V [Auto] at either 3.8GHz (BCLK of 200, 19X) or 4.0GHz (BCLK of 200, 20X). At first I found these numbers to be rather unusual, until I looked at the Intel specifications: 322164-001 (Rev. 1 09/2009) vs 322164-003 (Rev. 3 06/2010) vs 322371-002 (Xeon 3400 (i7-800 twin except 1X less multiplier) Rev. 2 01/2010).

Table 7.4 numbers are;

322164-001 (Max, for Min subtract 0.3V): VCC 1.55V, VTT 1.21V, VDDQ 1.65V, VCCPLL 1.98V

322164-003 (Max, for Min subtract 0.3V): VCC 1.40V, VTT 1.40V, VDDQ 1.80V, VCCPLL 1.98V

322371-002 (Max, for Min subtract 0.3V): VCC 1.40V, VTT 1.40V, VDDQ 1.80V, VCCPLL 1.98V

So VCC (CPU) went from 1.55V to 1.40V (in line with Xeon 3400).
So VTT (QPI/VTT Voltage) went from 1.21V to 1.40V (in line with Xeon 3400).
So VDDQ (memory) went from 1.65V to 1.80V (in line with Xeon 3400).

In light of these revised numbers, I would strongly suggest that Gigabyte update all their BIOS to reflect these new numbers (e. g. for QPI/VTT Voltages change pink colored voltages between 1.22V and 1.40V to white color for GA-P55M-UD4 future (F10) BIOS). Plus updated BIOS's supporting the most recent Intel CPU's (e. g. I7-875 and I7-880) for all compatible LGA1156 Gigabyte MB's.

I and the Gigabyte user community would greatly appreciate your cooperation in this matter.

TIA

Very Respectfully,
Francis E Sargent

[Lsdmeasap]

So the max Vtt also changed for non Xeon CPU's too?

Vtt and Dram really don't matter unless you are not setting them yourself, if you are then all you need to ensure is that you keep QPI/Vtt within .5 of the dram voltage and you can use and Vdimm you like as long as you keep QPI/Vtt within the .5 limit and under Max - if you want :)