Overclocking Q6600 G0 on Asus P5N32-E SLI Plus up to 3.3GHz

[verdant]

PC System

 

My PC system is based on an Asus P5N32-E SLI Plus motherboard fitted with an Intel Core2 Quad Q6600 [Kentsfield 65nm] G0 (SLACR) version 2.40GHz CPU with VID=1.3000V (according to CPU-Z) and with 2 x 2GB 667Mhz RAM and 2 x 1GB 667MHz RAM, and running off an Arctic Power 700W PSU.

 

It is fitted with Arctic Cooling Freezer 7 Pro CPU cooler usually running under PWM control (Q-fan mode). In order to clear the adjacent Southbridge heatpipe-heatsink at the top of the motherboard, the Freezer 7 Pro CPU cooler is mounted with its fan facing towards the bottom of the PC case i.e. towards the graphics card. Further thoughts on this.... it is not a bad orientation in my specific PC case cooling set-up, despite not being the recommended orientation, as (1) the case side fan blows onto the top cooling fin face-on and onto the tops of the 6 heat pipes that are all on the same elevation; (2) the cooler fan is now blowing upward past the cooling fins in the vertical direction, i.e. the same direction as the rising hot air in the case; (3) the rear case extract fan and PSU intake fans are now both drawing air from the vicinity of the fins; and (4) the CPU Cooler does not prevent the case side fan airstream from blowing directly onto the Northbridge and Southbridge heatpipe terminating heatsinks surrounding the CPU.....

 

The PC case has a 250mm variable speed side case fan (set to rotate at its lowest speed of 600 rpm) blowing air into the PC case directly onto the motherboard and it components, plus two 120mm Akasa Amber Ultra Quiet case fans (running full speed) mounted on silicone rubber anti-vibration mounts; one at the rear and one at the front of the PC case, both extracting air from the case and running at full speed.

 

The graphics card is a Gigabyte Silent-Pipe II 8600GT 256MB DDR3 NX86T256H (600Mhz Core and 720MHz Memory) Fanless card for quietness and no worries about future GPU fan failure etc.

 

The Northbridge chipset has a Scythe Mini-Kase Ultra 40mm Quiet Cooling fan mounted on its finned heatsink to blow air down on it (running full speed), while the Southbridge chipset has a Rasurbo 40mm Quiet Cooling fan (with its 4 mounting screws partially screwed into the fan frame) mounted on its flat heatsink to blow air down on it (running in Q-Fan mode). These fans are mounted using "blobs" of Homelux OBO BathSeal Waterproof Fixing Adhesive tape (Butyl rubber adhesive with very good holding power against gravity [but still removable] and vibration damping behaviour, with a maximum service temperature of 93ºC)

 

There is a Noctua NF-R8 80mm Quiet case fan mounted (running full speed), again using "blobs" of Homelux OBO BathSeal Waterproof Fixing Adhesive tape (butyl rubber adhesive – removable but strongly adhesive with a maximum service temperature of 93ºC), parallel to the side case fan and the RHS of the side case fan motor, forming a contra-rotating fan setup blowing air on the RAM modules and motherboard.

 

Initially the motherboard came with the 0805 BIOS installed but this did not allow stable overclocking beyond 2.7GHz. So I upgraded the BIOS to the 0901, 1002, and 1003 versions – still no success! I had to downgrade these other BIOS's to the 0803 version using the AWDFLASH.exe v1.31 and 0803.bin files copied onto a Bootable USB flash memory stick, and then entered

 

AWDFLASH.exe 0803.bin /py /sn /f

 

at the USB Drive letter prompt to force a BIOS downgrade.

 

Source for 0803 BIOS:

 

http://www.box.net/shared/sb3cl2ecsq

 

Source for software to make a Bootable USB flash memory stick:

 

http://files.extremeoverclocking.com/file.php?f=197

Overclock Settings

 

3.3GHz (Bus Speed 366.67 x 9.0) CPU-Z Core Voltage 1.456V

3.2GHz (Bus Speed 355.75 x 9.0) CPU-Z Core Voltage 1.408V

3.0GHz (Bus Speed 333.33 x 9.0) CPU-Z Core Voltage 1.360V

 

CPU-Z Validation Entry

 

OVERCLOCK AT YOUR OWN RISK - NO WARRANTY IS IMPLIED OR GIVEN WITH ABOVE COMPONENTS & 0803 SLIC BIOS & THE BIOS SETTINGS BELOW.

 

Overclocking Screen

 

Memory Timing Setting [All AUTO]

Spread Spectrum Control [All DISABLED] - for maximum performance

CPU Internal Thermal Control [AUTO]

Limit CPUID MaxVal [DISABLED]

Enhanced C1 (C1E) [DISABLED]

Execute Disable Bit [ENABLED]

Virtualization Technology [DISABLED] Does not appear to make a difference whether ENABLED or DISABLED.

Enhanced Intel Speedstep Technology [DISABLED]

LDT Frequency [5x]

FSB & Memory Config. Screen

 

FSB Memory Clock Mode [uNLINKED]

FSB (QDR)MHz [1467] for 3.3GHz, [1423] for 3.2GHz, [1333] for 3.0GHz

FSB (DDR) MHz [667] for 3.3GHz, 3.2GHz, and 3.0GHz

 

Overvoltage Screen

 

Vcore (V) [1.40000V] for 3.3GHz, [1.35000V] for 3.2GHz, [1.30000V] for 3.0GHz

Memory (V) [1.85V] (as my RAM is rated 1.8V)

1.2V HT (V) [1.30V] for 3.3GHz, [1.20V] for 3.2GHz, [1.20V] for 3.0GHz

NB Core (V) [1.40V] for 3.3GHz, [1.30V] for 3.2GHz, [1.30V] for 3.0GHz

SB Core (V) [1.60V] for 3.3GHz, [1.50V] for 3.2GHz, [1.50V] for 3.0GHz

CPU VTT (V) [1.40V] for 3.3GHz, [1.35V] for 3.2GHz, [1.30V] for 3.0GHz

DDRII Controller Ref Voltage [AUTO]

DDRII Channel A Ref Voltage [AUTO]

DDRII Channel B Ref Voltage [AUTO]

Example Normal Use Temperatures (using MS Word with CPU Fan in PWM Mode

and 22ºC room temperature)

 

3.0GHz - MOBO 31ºC CPU Case 26-28ºC CPU Core Max. 46ºC

CPU Fan PWM mode ~ 812-820rpm

 

3.2GHz - MOBO 31ºC CPU Case 29-31ºC CPU Core Max. 50ºC

CPU Fan PWM mode ~ 812-820rpm

 

3.3GHz - MOBO 31ºC CPU Case 32-34ºC CPU Core Max. 52ºC

CPU Fan PWM mode ~ 840-870rpm

Prime95 V25.6 Torture Testing (with CPU Fan in PWM Mode)

 

3.0GHz tested stable under Prime95 v25.6 Torture Test on all cores for 45mins before I stopped the testing. CPU Core Max. 66ºC and CPU Case Max. 52ºC.

 

3.2GHz tested stable under Prime95 v25.6 Torture Test on all cores for 45mins before I stopped the testing. CPU Core Max. 69ºC and CPU Case Max. 56ºC.

 

3.3GHz tested stable under Prime95 v25.6 Torture Test on all cores for 45mins before I stopped the testing. CPU Core Max. 72ºC and CPU Case Max 64ºC.

 

With the Arctic Cooling Freezer 7 Pro CPU cooler fan running at its maximum speed (Duty Cycle Mode 100%), at 3.0GHz idle, I achieved a temperature drop of 8ºC from a 26ºC CPU case temperature and 46ºC maximum core temperature (818 rpm under PWM control) to a 18ºC CPU case temperature and 38ºC maximum core temperature.

 

A similar temperature drop should occur at 3.3GHz under Prime95 load with the Arctic Cooling Freezer 7 Pro CPU cooler fan running at its maximum speed (nominally 2600 rpm according to SpeedFan 4.34) meaning that the maximum CPU Case temperature should be around 56ºC (N.B. the Intel thermal specification is 71ºC for the Q6600 G0 CPU and the Maximum Core Voltage is 1.5V) and the maximum CPU Core temperature around 64ºC. This was confirmed by the test results below.

Prime95 V25.6 Torture Testing (with CPU Fan in Duty Cycle Mode 100%)

 

3.3GHz tested stable under Prime95 v25.6 Torture Test on all cores for 45mins before I stopped the testing. CPU Core Max. 65ºC and CPU Case Max. 55ºC.

 

According the Asus Probe II V1.04.51 DMI Information, the maximum speed of the CPU is 3.8GHz, but I have not fully successfully overclocked to 3.4GHz yet; Vista 64 Ultimate is currently "freezing" post-login…….

 

In any event, I would want to ensure that, under Prime95 v25.6 Torture Testing for at least 45 minutes, the maximum CPU Core temperature does not exceed 65ºC at any point, to extend the CPU life, even though by some accounts the Q6600 G0 Version CPU is rated to 105ºC Tjunction and a thermal halt temperature of 120ºC; see http://www.hardforum.com/showthread.php?t=1302592

 

I do not believe that the Arctic Cooling Freezer 7 Pro can ensure this but unfortunately my present PC case (XClio 3060) cannot accommodate a taller heatsink cooler like the Scythe Miné or Thermaltake Big TypVX or or Tuniq Tower 120 etc. Also these coolers place a "heavy" cantilever load on a motherboard with implications for motherboard longevity…..

 

At present I am focussed on value for money enhanced productivity with video encoding etc. rather than just overclocking for fun...... so have not considered phase change cooling etc.....