Hello One Hello All, It has been alittle time since the launch and the retail availbility of Intel new Sandy Bridge CPUs ( especially K parts ) as well as their corresponding P67 Motherboards. We at ASUS would like to first and foremost thank all the users who have once again trusted in ASUS and purchased one of our P8P67 Series of motherboards. We have worked quite hard to ensure a quality range of boards with a quality bios are ready at the time of launch. With that noted there are alot of changes that users are going to need to be aware of. As such I am releasing this information in hope users will know how to best use their boards and new UEFI options. Hopefully this guide will provide a solid detailing of many of the new aspects users are interested should there be additional questions, concerns or inqueries please let me know and i will do my best to reply. Lastly as always ASUS holds no liability for any damage you or your hardware may incur during the pursuits of overclocking. I have detailed our recommendations to maximize the overclocking potential / scaling on ASUS P67 series of motherboards. This Guide has been developed after extensive internal testing across multiple boards, multiple bios builds and a high sampling rate of both D1 and D2 CPUs. While this guide is not a definitive article listing every possible overclocking combination, the information contained listed is providing repeatable results in our testing. Of course the quality of the cpu and cooling is very important but overall we think the results on our boards should exceed those of others at like settings. Expectations regarding K series overclocking in general and on ASUS P67 motherboardsPrior to the recommendations on overclocking the K series, I am outlining our results to set expectations. The results below are based on the range of the CPU turbo multiplier when overclocking. Results are representative of 100 D2 CPUs that were binned and tested for stability under load; these results will most likely represent retail CPUs. 1. Approximately 50% of CPUs can go up to 4.4~4.5 GHz 2. Approximately 40% of CPUs can go up to 4.6~4.7 GHz 3. Approximately 10% of CPUs can go up to 4.8~5 GHz (50+ multipliers are about 2% of this group) Additionally it is recommended to keep 「C1E」and「EIST」option enabled for the best overclock scaling. This is different than previous Intel overclocking expectations where the best scaling was with disabled power states or power management options. Update specific to D2 and retail parts: Jan 11 2001 As always ASUS strives to be at the forefront of performance and functionality offered by a quality bios. Keeping this in mind ASUS has been actively working in conjunction with Intel to optimize overclocking potential on ASUS P8P67 motherboards and K series CPUs. With the latest bios revisions ( 1000 series ) or 600 series for ROG specific optimizations have been made to the microcode and corresponding tables that relate to D2 and retail parts. These are improvement are in addition to general improvements in all respects. Present with this new build of the UEFI is a new option. This option / value is Intel PPL Overvoltage this option furthers multiplier scaling considerably.* In addition due to the increase in scaling more exotic forms of cooling cannot be used and will be needed under certain multiplier ranges and corresponding voltages. The general maximum range for the highest performing dual fan air based heastinks still remains 50x to 52x. * Intel PPL Overvoltage ( for increased K series overclocking set to enabled ) Overall in our ongoing internal tests the maximum frequency now achievable ( under LN2 ) is 5.8GHz. At this time we do not have a compiled database to reference improvements in the overall scaling range or new % of CPUs able to hit 50+ multis. With that noted currently we are seeing generally a minimum of 2 multi to as much as 7 multi increases with this value enabled on applicable D2 and retail parts. Example A D2 sample with peak multiplier of 44 with PPL option enabled and corresponding voltage applied we have seen results of a stable 50 multiplier now able to post / boot and be held. ( previously without the PLL value the same CPU would failed to compelte a boot with a any multi exceeding 45 ) In addition to the increase of the multiplier range a side effect is additional Vcore needed to compensate for maintained post/boot and stability tests. The new voltage level do not align with standard voltage scaling ( on CPU already able to hit / sustain comparable multipliers. Example Generally 4.8GHz stability can be achieved at 1.400 1.425 Vcore now with PLL enabled D2 parts exceeding their previous max multiplier the increase in voltage would be 1.425 1.450. It is important to note this option should generally only be used with D2 and retail parts NOT D1 parts. Internally we have partial results to indicate degradation of stability at previously reached multiplier values. Some internal testing has shown on limited samples that some improvement is possible (generally in the range of 1 multi possibly 2 ) In addition continued testing with the PPL option enabled and D2 or retail parts have shown some benefits to CStates being disabled when approaching, at or exceeding a 50x multiplier. An important note to keep in mind is that disabling CStates can considerably affect HD performance ( especially SATA6G ) Please keep this in mind when going for the highest level overclocks. Expectations regarding K series overclocking implementation options on ASUS motherboards Using Speedstep or Not Using Speedstep Quick Note on implementation of K series Turbo Multiplier control While our Digi+ VRM option has extensive adjustments to voltages, multipliers and Bclk (such as .1 increments ex 106.8 or 108.1) one specific difference is noted below. With the latest bios revision ASUS motherboards have a high level of flexibility at customizing the efficiency and consistency of the overclock values set in the UEFI. It possible to overclock while keeping speedstep enabled and use the offset voltage method for Vcore increase this will provide the overall best in temperature and heatsink performance as well as generally efficiency and extension of the lifespan of the motherboards its components and the CPU. This is due to the Turbo Multiplier working and exucting ramping as Intel intended. Example leaving all CStates and Speedstep enabled will allow the CPU to idle down in Vcore and frequency ( 1600MHz ) and ramp up when under load to 4.8GHz when needed. Should there be interest in consistently maintain a desired clock frequency users can disable Speedstep and still keep Intel Turbo multiplier overclocking enabled. Please note that overall disabling or adjustments of Speedstep or CStates do not affect overclocking range ( this is different than previous generations when power saving states were advised to be disabled when exceeding 3.8 to 4.0GHz ). K series overclocking benefits on different ASUS P67 motherboards Quick Note Regarding Motherboard Stack What does going higher in the board stack provide overclocking wise? ASUS entire line of P67 motherboards features a class leading and high performance Digi+ VRM implementation that allows for superior overclocking performance; there will be differences between boards. While our entire board lineup has been internally tested to fully support K series processors, when overclocking in multiplier ranges of 50 to 54x the higher end boards will benefit in two key categories. 1. Better Vdroop efficiency. 2. The ability to help drive and sustain a 50+ high load Overclock under maximum loads. Examples of boards that focus on this level are our Deluxe, WS, SABERTOOTH, and Maximus IV Extreme K series overclocking multipier wall Quick Note regarding the K series multiplier wall Previous generations of Intel CPUs due to architectural differences had two aspects that could readily change OC scaling potential. These two factors were TDP (heat output under load) as well as core (CPU/VTT ) voltage being supplied. With previous generation cpus, improvements such as high end air cooling, water cooling or more extreme forms like LN2 in addition to extreme voltage increases could potentially provide increases in clock speeds on a continual ramp until the limits of the CPU were reached. This is not the case with K series on the P67 chipset. In internal testing we have found that maximum multipliers in excess of 50 (up to 54) have been able to be realized with full stability under Air Cooling and with cpu vid voltages under 1.525V. In fact, the processors will actually start to downclock as they get colder with temperatures under -20C actually performing worse than the retail air cooler at times. The processors optimal range for performance is around 15~20C in our testing. An example is noted below. Should you have a CPU in hand that reaches a 47 multi easily ( posting/booting and running full stability tests at a set Vcore of 1.375V) you would then attempt to jump to the next multiplier. With the K series CPUs you may have reached the max multi regardless of the cooling or voltage used. Adjustments to either of these settings will not change the ability of the board and CPU to post at 48x. The only time it will continue to scale would be if the CPU in hand supports higher multipliers or can be finely tweaked to reach that next multi, in this case we suggest using the 47x multi and adjusting Bclk until you reach the limits of stability. 100BCLK + 47 Turbo Multiplier with Vcore of 1.375 and LLC ( load line calibration of ultra high = 4.7GHz 100BCLK + 48 Turbo Multiplier with Vcore of 1.400 and LLC ( load line calibration of ultra high ) = no boot 100BCLK + 48 Turbo Multiplier with Vcore of 1.425 and LLC ( load line calibration of ultra high ) = no boot 100BCLK + 48 Turbo Multiplier with Vcore of 1.450 and LLC ( load line calibration of ultra high ) = no boot It is important to note that a post will still occur with a multi present that is at the multi wall. This is because only when the OS begins to initialize and the Turbo ratio is initialized ( kicks in and ramps up ) that Turbo Multiplier will be raised to defined multi at this point it will then cease to boot due to the multiplier wall being reached. K series overclocking and voltage range recommendations Quick Note regarding Voltage Scaling Internal binning of both D1 and D2 parts we discovered consistent voltage scaling patterns. 1. For K series parts, the stock voltage supplied will allow for consistent overclocking generally up to a multiplier of 43x. There is potential for the multi to be raised to 44x depending on the load induced. This default voltage range be approx 1.240 to 1.260 under load. 2. Increased range between 44 to 47x multipliers will generally require a voltage range between 1.30 to 1.375V with an LLC recommended setting of high to ultra high. 3. Increasing the range between 48 to 50x multiplier will generally require a voltage range between 1.40 to 1.500 with a LLC recommended setting of ultra high. 4. Increased range between 50 to 52 (52 generally considered peak max multiplier except for rare 54x parts) will generally require a CPU voltage range between 1.515 to 1.535V with LLC at Ultra High and potential fine adjustments to the CPU skew range. Overall a key item to note is the best voltage to oc scaling range potential for the turbo multiplier is 1.400 to 1.425 vcore. Using this voltage range with an LLC recommendation of ultra high will generally provide the best scaling potential with proper load temperatures*. We have generally found exceeding this voltage will not provide additional scaling or will increase load temperatures to a high level with synthetic load applications ( like Prime, Linx, OCCT ). Should you use more realistic loading testing (our recommendation is a combination of AIDA64 stress test, PC Mark Vantage) then temperatures under will be considerably under the max TDP rating. *cooling recommendation and test performed with CoolerMaster Hyper 212+ with Single Fan, this is the minimum recommendation for multis above 46x. For 50+ multis we recommend a dual fan configuration with this cooler or improved cooling. K series overclocking benefits from non CPU Voltage based adjustments ( UEFI values for power management , Cstates, PCH etc ) Quick note regarding bios values that should be adjusted Over a long test and tune cycle, ASUS has developed a class leading bios with superior auto overclocking. This superior performance translates to overclocking in two ways, manually or automatically via the use of our Auto Tuning application. Keeping in mind that most retail K series parts will be sub 50 multi capable, our Auto Tuning application has been designed to Auto Tune up to a range of 50 should the CPU support it. In effect reaching the absolute maximum clock a user can reach manually. Additionally Auto Tuning can serve as a good option for seeing the potential in the CPU and max multiplier it may have before fine tuning the system. An example is shown below. P8P67 (Standard) 2600K, Hyper 212+, Corsair 1600C8 memory 4 dimm. Should you continue with manual overclocking, these are the advised recommended values. 4.7GHz or Below All bios values to Auto except for those noted- CPU Turbo Multiplier Dram Voltage to specification Internal testing has shown Auto Values will allow for stability in all forms of testing including high synthetic high load applications (Linx, Prime95, Occt ). In the event general stability is not achieved in these synthetic high load applications, you can adjust the noted values for improved stability. Digi + VRM options VRM frequency to 350 Requires setting to manual adjustment and entering the specified value. 4.7GHz and above CPU Turbo Multiplier To desired value Dram Voltage to specification Digi + VRM options VRM Frequency change to 350 this value will allow for scaling to 50+ multi without issues Phase Control change to extreme this value will allow for scaling to 50+ multi without issues Duty Control change to extreme - this value will for scaling to 50+ multi without issues. No other values need to be changed. Unless otherwise noted all other UEFI values used are AUTO. K series overclocking and its affect on subsystem performance especially HD performance Quick note regarding options that can affect subsystem performance It is NOT advised to make adjustments to Cstates as this can considerably affect hard drive throughput performance ( especially SATA6G SSD or Sandforce 2 based SSD ). It is recommended that all CPU power configuration states be left on their default parameters. Overclocking tests have shown internally no increase in multiplier scaling when adjusting these values. * under special cases with high multi capable CPUs and synthetic high load applications ( Linx, Prime, Occt ) it may required C states to be disabled. This has generally only been confirmed for some 51-54 multi capable CPUs. K series overclocking benefits from adjustments to Digi+ VRM options Advanced Digi+ VRM options recommendations VCCSA This has shown in internal testing not to improve overclocking, yet may still maintain the same level of stability while being lowered from its default value in order to keep the CPU cooler. VCCIO The adjustment of this voltage may help to slightly improve the overclocking capability of the IMC / DRAM, even though the default voltage is enough to run at a 2133MHz DRAM frequency. A 1.20v setting is more than adequate to maximize Memory overclocks in most cases. CPU PLL This setting did not improve overclocking, yet the user can maintain the same level of stability while lowering its default value in order to keep the CPU cooler. PCH Voltage This setting did not improve overclocking, yet the user can maintain the same level of stability while lowering its default value in order to keep the CPU/PCH cooler. PCH PLL This setting did not improve overclocking, yet the user can maintain the same level of stability while lowering its default value in order to keep the CPU/PCH cooler. K series overclocking and how BCLK is affected and how to best optimize BCLK scaling Quick Note for BCLK tuning BCLK clocking is considerably reduced with this new CPU architecture and as such it is recommended to focus on Turbo Multiplier adjustments for overclocking. With that noted should you choose to make adjustments to the BCLK, ASUS has enabled extensive control to maximizing scaling. Internal testing shows BCLK ranges from 102 to 109.1 with the largest level of scaling dependency placed on the quality of the CPU. CPU Frequency and speed is also directly tied to BCLK scaling. Internally we know that BCLK tuning largely depends on the CPU with approximately but we have noticed up to a 20% dependency on scaling potential based on the board design and PWM utilized. At 4.9GHz, generally the maximum clock speed will not change with a different combination of multi and bclk in this particular example. Example- 100x49 = 4.9GHz 103x48 = 4.9xxGHz Generally the CPU will not do much more than what your maximum CPU multiplier range is in most cases. Keeping this in mind, we offer very fine adjustments down to 0.1x increments to allow for the maximum BCLK tuning. Lastly when considering adjustments to the BLCK range, it is important to remember it will affect the memory divider/strap and DRAM frequency. Keeping this in mind you may want to adjust to a lower divider if your memory does not higher frequencies. This especially true when attempting to sustain 4 dimm and high memory density configurations with high BCLK and high Turbo Multiplier values.