Core i7 4Ghz Club & Overclocking Guide

[Deton]

Core i7 owners please come join us and share your overclocking expertise, tips, secret and discussion on everything relate to
Asus X58 boards or any others and Core i7 processors.

[Deton]

Intel introduced the LGA1366 new platform for the Core i7 processor architecture. This new chip deliver significantly better performance per clock cycle
compared to the previous LGA775 system, also it has more power-efficient than its predecessors.

No doubt the Core i7 (Nahalem) is a great chip and also it has much more complex circuitry design than the Penryn family, it can handles everything you throw at it with ease.
However, overclocking Nahalem is a little bit different compare to previous generation Core 2 processors.
Consequently, the same overclocking principles apply to these new systems as well.

The Penryn processors which feature a Front Side Bus (FS and an external Memory Control Hub (MCH – Northbridge); they are completely opposite to the Nahalem,
it has onboard (integrated) MCH, a QPI (Quick Path Interconnect) bus, an Uncore clock and a Bclock (base bus frequency) constitutes each of the other component clock speeds.

Before I’m tutoring you through the overclocking process I would like to disclaim to the fact that overclocking a CPU is exceeding manufacturer recommendations clock speed and voltage,
there are some risks involved. Increasing CPU clock speed and excessively voltage can cause system instability or can permanent damage.
Therefore, I'm not responsible for any damages or lost of your hardware if you're using my guide.

This guide is not attending for beginners; you must familiar with overclocking fundamental process.
However, I'm try to make it simple as I can and the beginer can follow it as well.

[Deton]

When overclocking LGA775 systems is relatively increasing the processor bus frequency, as the processor bus frequency increases
so as the processor and memory frequencies are proportionally increases as well.
In this situation, overclocking is completely different with Core i7 processors.




These processors not only have 8MB shared L3 cache and integrated memory controller but they use a totally new series interface to connect to the chipset and the base bus frequency (Bclock) play a major role for this new system. Core i7 also has 4 new sets of multiplier; you can find them as following;

• CPU frequency = Bclock x CPU multiplier (locked multiplier unless you have the Extreme Edition then you can move upward)
• Uncore frequency = Bclock x Uncore multiplier
• Memory frequency = Bclock x Memory multiplier
• QPI frequency = Bclock x QPI multiplier

Bclock
This is the base bus frequency; it is similar to the FSB. This base bus frequency has its influence to the Uncore,
memory clock, QPI clock and CPU clock components; when you increasing it will overclock everything at once. The Bclock stock frequency is 133Mhz.



Uncore
The Uncore clock is the speeds of the L3 cache and the on-die MCH. Since both memory and Uncore clock share the same reference clock (Bclock)
therefore the Uncore clock must always be equal or twice greater than the memory clock.

Example: The Uncore clock speed equal Bclock multiply the Uncore multiplier.
Bclock = 133Mhz
Memory multiplier = 12
Uncore = 133Mhz x 2(12) Uncore multiplier = 3192Mhz



Memory clock
The memory clock refers to RAM speeds, the memory clock speed is found as follow;
Memory clock speed = memory multiplier x Bclock

Example:
Bclock = 133Mhz
Memory multiplier = 12
Memory clock = 133Mhz x 12 = 2666Mhz



QPI clock
QuickPath Interconnect clock speed determines the bandwidth available to all the components connected to it, such as RAM, GPUs, CPU, etc.
QPI bus should be kept close to stock speeds, and its multiplier would have to be lowered in the case that the Bclock is raised. The lowest QPI multiplier available is 18x.
QPI clock speed = Bclock x QPI multiplier
Example:
Bclock = 133Mhz
QPI multiplier = 18
QPI clock speed = 133Mhz x 18 = 2394Mhz



CPU clock
The CPU clock is the processor clock frequency which the main unit that we want to enhance its speed.
The equation can be found as following;
CPU clock speed = Bclock x CPU multiplier

Example:
Bclock = 133Mhz
CPU multiplier = 20 (we will be using i7 920 has a locked multiplier at 20)
CPU clock speed = 133mhz x 20 = 2660Mh

[Deton]

Turbo Mode
Intel designed Core i7 to actually overclock the CPU by itself for you. It’s a feature which can be toggled on/off in the BIOS or through software
so that the extra horsepower can be supplied to active cores. The active cores are then adjusted or overclocked by pump up the multiplier one notch for additional
performance so that they perform faster. However, the Turbo mode only active if your processor’s thermal stay within its specification, which is mean if you have poor cooler
than it won’t switch over Turbo mode.

Example: if you have i7 920 with locked multiplier at 20x, the board will pump it to 21x when it’s needed.

Consequently, it is not extremely helpful when it comes to high-end overclocking. If you’re a dedicated overclocker, I would recommend disabling this feature to force consistent clock speeds.

Hyper-Threading
Welcome back HT.
HyperThreading was introduced back then the Pentium 4 chip, it is a virtual multiple threading; when this feature enable, it’s allow each core to have two simultaneous threads for each core to processing. A quad-core processor with Hyper-Threading will show eight cores in the operating system but it doesn’t have better performance than a true Octa-core system, but it’s definitely have better performance advantage in heavily multi-thread applications when it enables compared to the same system with Hyper-Threading disabled.

However, Hyper-Threading could hindered the performance if the applications are not multi-thread but in general with the Hyper-Thread smooth out multitasking and in applications that were optimized for multi-threading, you would see a modest performance advantage. The good thing is you can toggle this option on/off in the bios to suite your computing needs.





Voltages
It’s a known fact that overclocking can decrease the life of the CPU especially when it overvoltage.
Normally when overclocking you do need to increase the CPU, MCH and RAM voltages to achieve higher overclocking and utilize its stability. When you increase these voltages are often they produce extra heat to the components. So increase the value in small increments at a time with precaution, and never go over each components max voltage specification or you can cause permanent damage each component if it’s raised too high.

vCore = the voltage for the CPU cores
vTT = the voltage value for Uncore & MCH
vdimm = RAM module voltage


Temperature
Increasing CPU's voltage or its clock speed will generate extra heat, especially when you have Turbo Mode or Hyper-Threading enables. Therefore, you should make sure you have an adequate cooler before you overclocking your processor. Core i7 have stock of 130W TDP and it will jumps up to approximately 147w and can produce heat up to 250-290w when it overclocked.

How to determine if you have an adequate cooler before you proceed the overclocking?
Using default stock settings open any thermal monitor program of your choice to check the CPU temperature. If the delta temperature (the different temperature) is within 5°C – 7°C with the ambient temp then your cooler is adequate at idle loading.

Example:
if you have ambient temp at 25°C and the CPU temp is 30°C then you are safe to use the cooler, and if it is more than 10°C then you should investing in a better cooler before you start overclocking your processor.

Another way to determine if your HFS is good enough to cool overclocked i7;
Leave everything at stock speed setting, run Prime95 at all threads with HT/Turbo enables. Now monitoring the temperature for few minutes; if your load temps reached beyond 70°C at this point then don’t even thinking of overclocking your CPU until you upgrade the HFS.

I would recommend, to keep the cores temperature at around 70c - 75c under load, this will give you about 5c of headroom for the hot summer days.

[Deton]

If you have a hard time to figure out all the above equations manually then you can download this Nahalem Overclocking Calculator. This is handy and dandy tool to save you all the guess work.
http://icrontic.com/downloads/nehale...ing-calculator

[Deton]

The main three pieces of the hardware I will be using for this guide are the Asus P6T Deluxe, Core i7 920 and Corsair XMS3 TR3X6G1600C8D Dominator.
If you have the 965 processor then you are very lucky person, this processor will make your overclock as a brezze.

You can keep Bclk low and just upwards the multiplier and it will flies. The overclocking principles still apply the same as you have 920, 940 or 965 version.


In BIOS Ai Tweaker menu set following options as below;


AI Overclock Tuner - Manual
You need to set this option at Manual or D.O.C.P or X.M.P before you start to customize the other features.
Since the Dominator is X.M.P ready so I chose this option over the Manual, if your memory is not X.M.P ready then you have to use Manual option and manually set the memory timings.

Although if you're lucky enough to have XMP ready memory you might want to try that - 1,600MHz sets the QPI link to 200MHz - just what we needed for 4GHz.

Intel Turbo Mode - Disable
I disabled it so as it would not interfere with the overclock.
However you can leave on later on if you want use new Intel low power states.
Normally this affects how the CPU overclocks and in extreme cases expect it will, because the on/off effect to the CPU frequency and voltages as the C-state changes.


BCLK Frequency – 200Mhz
BCLK = Base clock. This affects the QPI and uncore (L3 cache, northbridge) frequency too.
We’ll be shooting for 4Ghz, so we will set the Bclock at 200Mhz.

CPU Voltage – 1.35v (max 1.55v)
At this value is plenty of juice to fed the i7 920, depending on your own CPU’s need, it might be happy with less voltage.
According to Intel white sheet, the maximum recommend voltage is 1.3675v. However, you still can go up to 1.4v-1.47v and still safe, of course it’s depending on what type of cooler you are using.

DRAM Frequency - 1,600MHz
Since I’m using Corsair Dominator 1600Mhz, therefore I will running it at stock speed. I’m not going to overclock the RAM in this guide.
You’ll have more chances to get the system rock solid stable if you run the memory slower speeds if you can. However, you can overclock it later on when you have a stable overclocked.

CPU PLL Voltage – 1.96v (max 1.89v)
Honestly, I’ve to play with this voltage more, Intel recommended is 1.89v max but I’m using 1.96v for now.

QPI/DRAM Voltage - 1.35v
Don’t confuse this voltage with the actual memory voltage. Increasing this is also necessary as it helps overclock the base frequency as the uncore area overclocks increase in relation to the CPU core overclocks. This voltage is tied to actual DRAM voltage - the two are directly connected on the motherboard. You'll need to increase this to keep the CPU safe.

You should keep this voltage and Vram voltage the same or no more/less than 0.5v.

[Deton]

DRAM Voltage - 1.65V Max
There’s a warning that you should keep this voltage max at 1.65v, anything above this have the potential to damage the CPU.
However, if you can keep the CPU Uncore voltage within 0.5v difference of the DRAM voltage and there’s no problem.



A little CPU Differential Amplitude will help with overclocking and turn off some unused features.



And keep Hardware Prefetcher and Hyper Threading on will improve performance.



With ACPI 2 enable, it's help to keep the clocks on Core i7

If you are familiar with Intel systems, the best thing to do is treat QPI frequency like you would with Front Side Bus and cranking up the QPI also levies another advantage - increased memory frequencies. Because the Core i7 920 uses the basic 4.8GT/s QPI frequency there is no option available here to adjust it, so you don't have to worry about it, however being able to see what its "final frequency" post-overclock would be incredibly useful.

I found that enabling APCI2 (High Performance Event Timer), is critical for keeping the clocks on Core i7 CPUs accurate.
Without it turned on, the multiplier jumps around crazily, but with it on, the multiplier reading is solid and the clock frequency only jitters very slightly according to fractional variations in the base clock.


Stability Stress Test
Now it’s time to check your overclocking for stability; the following are recommended software to use to test your overclocked i7.
Prime95
OCCT

Thermal monitoring software;
CoreTemp
RealTemp
Everest
HWMonitor

[Deton]

I wouldn’t recommend you to try this if you are on air cooler, at least you’re on water cooling or your processor will cry for help or the Turbo won’t active if your air cooler under its cooling power.



Now enable Turbo Mode and pump the CPU & QPI/DRAM Core up to 1.4125v, don’t forget to run Prime95 again to check the stability.
Notice: your result might be different due to each chip (processor) behave differently; you might need more voltage or less.
With the Bclk at 200 and with the Turbo kick in then processor will run at 4.2Ghz with HyperThread (8 cores), that’s one fast and smooth performance rig.



And don't forget to do stability test for this setting as well.

[Deton]

***NEW***

The following Bios settins are just sample guidelines. The result may varies for each hardware configuration.

Rampage II Extreme

Member	Benchwarmer	Bullydog	TechAnalyst	Karancho RC
Processor	920 D0:3.8Ghz HT&TURBO	920 D0:4.2Ghz HT&TURBO	965EE D0:4.0Ghz HT	920 D0:4.0Ghz HT
Batch #	3841A712			3841A712
RAM	6Gb OCZ Platinum 1600Mhz	6Gb Team Xtreem 1600Mhz	6Gb OCZ Flex 1866Mhz	6GB OCZ Gold 12800C8
Cooling Method	Air	Water	Air	Air
BIOS Version	1104	1206		1406
Extreme Tweaker
Ai OC Tuner	Manual	Manual	Manual	Manual
OC from CPU Level Up	Auto	Auto	greyed out	Auto
OC from Memory Level Up	Auto	Auto	Auto	Auto
CPU Ratio Settings	19.0	21	30	20
CPU Turbo Power Limit	Enabled	Enabled	Disabled
BCLK Freq	200	200	134	200
PCI-E Freq	100	100	100	100
DRAM	DDR3-1603Mhz	DDR3-1603Mhz	DDR3-1600Mhz
UCLK	3208Mhz	Auto	Auto	Auto
DRAM Timing Control	Manual set to 8-8-8-20	Manual set to 8-8-8-20	Manual 9-9-9	Manual 8-8-8-24
EPU II Phase Control	Full Phase	Full Phase	Full Phase	Full Phase
Load-Line Calibration	Auto	Enabled	Enabled	Enabled
CPU Differential Amplitude	Auto	Auto	Auto	Auto
Extreme OV	Enabled	Disabled	Disabled	Enabled
CPU Voltage	1.35	1.275	1.42	1.225v
CPU PLL Voltage	Auto	Auto	Auto	1.82917
QPI/DRAM Core Voltage	Auto	Auto	Auto	1.250
IOH - PCIE - ICH - PCIE	Auto	Auto	Auto	Auto
DRAM Buss Voltage	1.65681	1.65681	1.65	1.64356
CPU Spread Spectrum	Auto	Auto	Disabled	Disabled
PCIE Spread Spectrum	Auto	Auto	Disabled	Disabled
CPU Clock Skew	Auto	Auto	Auto	Auto
IOH Clock Skew	Auto	Auto	Auto	Auto
Advanced(CPU Configuration)
C1E Support	Disabled	Disabled	Disabled	Disabled
Hardware Pref.	Enabled	Enabled	Enabled	Enabled
Ajacent Cache Line Pref.	Enabled	Enabled	Enabled
Intel Virtual Tech.	Enabled	Enabled	Disabled	Enabled
CPU TM Function	Enabled	Enabled	Disabled	Disabled
Execute Disabled Bit	Enabled	Enabled	Disabled	Enabled
Intel HT Tech.	Enabled	Disabled	Enabled	Enabled
SpeedStep		Enabled	Disabled	Disabled
Turbo		Enabled		Disabled
Active Processor Cores	All	All	All	All
A20M	Disabled	Disabled	Disabled	Disabled
Intel C-State Tech.	Disabled	Disabled	Disabled	Disabled
Power
Suspend Mode	Auto	Auto		Auto
Repost Video On S3 Resume	No	No		No
ACPI 2.0 Support	Disabled	Disabled		Disabled
ACPI APIC Support	Enabled	Enabled		Enabled

P6T Deluxe

Member	Deton	Neo83	Anti5580	ZeroChill
Processor	920 C0:4.0Ghz HT&TURBO	920 D0:4.1Ghz HT	920 D0:4.0Ghz HT&TURBO	920 D0:4.2Ghz HT
Batch #				3849B018
RAM	6Gb Corsair Dominator 1600Mhz	6Gb OCZ 1333Mhz	6Gb Corsair Dominator	6Gb Corsair Dominator
Cooling Method	Water	Air	Water	Air
Board Version	1		2	2
BIOS Version	1504		504	610
Ai Tweaker
Ai Overclock Tuner	X.M.P.8-8-8-24	9-9-9	X.M.P	X.M.P
CPU Ratio Setting	Auto	21	20	21
Intel SpeedStep Tech	enabled	disabled	enabled	disabled
Intel Turbo Mode Tech	enabled	disabled	disabled	disabled
Bclk Frequency	200	195	200	200
PCIE Frequency	100	100	100	100
DRAM Frequency	DDR3-1603Mhz	DDR3-1330Mhz	DDR3-1603Mhz	DDR3-1603Mhz
UNCLK Frequency	3208Mhz	Auto	3208Mhz	3208Mhz
QPI Link Data Rate	7218MT/s	Auto	7218MT/s	7218MT/s
CPU Voltage	1.425	1.25	1.2625	1.275
CPU PLL Voltage	1.96	Auto	1.80	auto
QPI/DRAM Core Voltage	1.3875	Auto	1.20	1.35
IOH Voltage	Auto	1.3	1.24	auto
IOH PCIE Voltage	Auto	Auto	Auto	auto
ICH Voltage	Auto	1.3	1.10	auto
ICH PCIE Voltage	Auto	Auto	Auto	auto
DRAM Bus Voltage	1.66	1.65	1.66	1.66
DRAM DATA REF Voltage on CHA	Auto	Auto	Auto	Auto
DRAM CTRL REF Voltage on CHA	Auto	Auto	Auto	Auto
DRAM DATA REF Voltage on CHB	Auto	Auto	Auto	Auto
DRAM CTRL REF Voltage on CHB	Auto	Auto	Auto	Auto
DRAM DATA REF Voltage on CHC	Auto	Auto	Auto	Auto
DRAM CTRL REF Voltage on CHC	Auto	Auto	Auto	Auto
Load-Line Calibration	Enabled	Enabled	Enabled	Enabled
CPU Differential Amplitude	800mV	Auto	800mV	800mV
CPU Clock Skew	Auto	Auto	Auto	Auto
CPU Spread Spectrum	Disabled	Disabled	Disabled	Auto
IOH Clock Skew	Auto	Auto	Auto	Auto
PCIE Spread Spectrum	Disabled	Disabled	Disabled	Auto
Advanced
CPU Ratio Setting	Auto	21	Auto	21
C1E Support	Disabled	Disabled	Disabled	Disabled
Hardware Prefetcher	Enabled	Enabled	Enabled	Enabled
Adjacent Cache Line Prefetch	Enabled	Enabled	Enabled	Enabled
Intel Virtualization Tech	Disabled	Enabled	Disabled	Disabled
CPU TM Function	Disabled	Disabled	Disabled	Disabled
Execute Disable Bit	Enabled	Disabled	Enabled	Enabled
Intel HT Technology	Enabled	Enabled	Enabled	Enabled
Active Processor Cores	All	All	All	All
A20M	Disabled	Disabled	Disabled	Disabled
Intel SpeedStep Tech	Enabled	Disabled	Enabled	Disabled
Intel Turbo Mode Tech	Enabled	Disabled	Enabled	Disabled
Intel C-STATE Tech	Disabled	Disabled	Disabled	Disabled
Power
Suspend Mode	Auto			Auto
Repost Video on S3 Resume	Yes			Yes
ACPI 2.0 Support	Enabled			Enabled
ACPI APIC Support	Enabled			Enabled

EVGA CLASSIFIED

Member	Bullydog
Processor	920 D0:4.2Ghz HT&TURBO
Batch #
RAM	6Gb Team Xtreem 1866Mhz
Cooling Method	Water
Board Version
BIOS Version	S61A (date: 8/25/2009)
Voltage Control
eVGA Vdroop control	Without Vdroop
CPU VTT VOLTAGE	+175mV
CPU PLL VCORE	1.8
IOH PLL VCORE	1.8
QPI PLL VCORE	1.1
DIMM VCORE	1.65
DIMM DQ REF	+0mV
IOH VCORE	1.10
ICH VCORE	AUTO
VTT PWM FREQ	250KHZ
CPU PWM FREQ	800KHZ
CPU IMPEDENCE	AUTO
QPI SIGNAL COMPENSATION	AUTO
OVERCLOCK MENU
CPU CLOCK RATIO	X20
CPU HOST FREQUENCY	200
MCH STRAP	1600MHZ
CPU UNCORE FREQUENCY	3205MHZ
CPU CLOCK SKEW	0ps
SPREAD SPECTRUM	DISABLED
PCI-E	100
OC RECOVERY	ENABLED

[Deton]

MEMBER	BULLYDOG	DETON	Karancho RC	ZeroChill
CPU	920 D0	920 C0	920 D0	920 D0
OC	4.2Ghz	4.2Ghz	4.0Ghz	4.2ghz
Vcore	1.275v	1.425v	1.225v	1.275v
HT	enable	enable	enable	enable
TURBO	enable	enable	disable	disable
COOLING METHOD	Water	Water	Air	Air
SPECS	HeatKiller 3.0, Feser360, MCR220,MCP655, EK4870X2	Swiftech Apogee GTZ, MCR220 & MCR320, MCP655, XSPC Bay Res	Noctura NH-U12P	Thermalright Ultra-120 eXtreme RT 1366: dual-fan push/pull using Noiseblocker M12-P @ 1000-2000 rpm
No. OF LOOP	1	1
AMBIENT	24°C	21°C	26°C	28.4°C
CORE IDLE	41°c	38-42°C	42°C	43-45°C
CPU		27°C	36°C	42°C
CORE LOAD	78-79°c	62-78°C	66-72°C	79-83°C
CPU		62°C	55°C	77°C

*** Thank you to all members for submitted the temperature reading.***

Load temps were taking during 5 minutes IntelBurn Test and these figures might not 100% accurate.
They are just reference guideline to give you the idea how hot the OCed i7 will be, so make sure you have a good cooler before you consider overclock it.

[Deton]

reserved for future update 10

[Doctor_Death]

Deton, I think you forgot to mention for 920s and 940s , people with 965 Extremes will not be able to use this will they ?

[Deton]

Originally Posted by Doctor_Death

Deton, I think you forgot to mention for 920s and 940s , people with 965 Extremes will not be able to use this will they ?

Well anyone owns i7 can jump in, I don't want to specific the processor version here. As you know the new i7 lineup are coming out.

920/940 are the same chip, except 965 have upwards multiplier and faster QIP.

I'm sure 965 owners or any other X58 board owners can use this guide are guide-line as well.
Most 965 are run at slow Bclk and higher multiplier because they can easily achieve higher overclocking.

So the 4Ghz club is slightly different from the Max Clubs, no dedicated board here.
I'm expecting all PureOC Core i7 owners to jump on board here. Wanna to draw more member and traffic to PureOC? Then post, make this thread bigger and don't forget to add on some tags to this thread.

[bullydog]

Well done Deton, you did it again!
Very informative ... sufficient information for i7 newbies

[shattered.likeness]

Thanks Deton. And thanks to your guide, I am looking to upgrade to the i7 as well now.

[Rat]

They will they just also have the luxury of an unlocked multiplier.