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Lesson 05 - Overclocking from 3.7GHz to 4GHz and Memory Overclocking

 

Introduction

In this video we are going to replace the stock Intel cooler with an Arctic Cooling Freezer 7 Pro Rev.2 and then overclock the CPU from 3.7GHz to 4GHz and overclock the memory.

Replacing the Stock Intel CPU Cooler with an Arctic Cooling Freezer 7 Pro Rev.2

We've already removed the stock Intel cooler and cleaned the thermal compound off of the CPU as shown in Lesson 2.

To unbox the Freezer 7 Pro you need to turn it so you can see the specs on the back.  There are three plastic fasteners, two on either side and one at the bottom.  Once those are loose you can separate the front from the back and slide out the cooler.  Lift the cooler up and set it on its back to protect the pre-applied thermal compound.  There is an Intel bag with push pins and screws which we will be using.  The AMD bag has two metal pieces and screws used for installing the cooler onto an AMD CPU.  We won't be needing those so I'll set them aside.

The cooler comes with an Intel mounting plate.  On each corner of the plate there are 3 holes for the push pins to go through the mounting plate and through holes in the motherboard.  The holes closest to the center of the plate are used for installation onto a socket 775 motherboard.  The middle holes are for socket 1156 motherboards and the outer holes are for socket 1366 motherboards.  We have a socket 1366 motherboard so we will use the outer holes.

I'll set the mounting plate onto the motherboard so the outer holes are above the holes in the motherboard and the screw holes are facing the front and back of the computer.  The push pins are in sets of two.  The white shorter one with the arrow head looking tip goes through the mounting plate and motherboard.  The other black push pin goes through the first and wedges the arrow head outward to secure the mounting plate to the motherboard.

The push pins are very small so, to make it easier, I will use needle nose pliers to insert them.  Insert the white arrow head shaped one first into the outer hole.  Once it's partially in I'll let go of it and use the pliers to push it down.   I'll insert another white arrow head shaped push pin into the opposite corner of the plate the same way and then the two remaining corners.

Next, I'll get a grip on the head of the black spreader pin with my pliers and push it straight through the white arrow head shaped pin.  I'll do the same at the opposite corner from the first and then the final two.  The plate is secured to the motherboard.  If you need to remove the pins, use your needle nose pliers to pull straight up.  Twisting the pins will make them break off.

On the heat sink, the fan is covering up a screw hole we need to get to.  The plastic fan is held to the cooler on each side using a notch in the metal cooler.  I'll reach through the fan shroud and press outward to remove the fan from the cooler.

Next, I'll lower the heat sink onto the CPU and mounting plate making sure the direction of air flow from the cooler's fan is directed towards the rear exhaust fan.  On one side of the cooler, use your philips or plus screwdriver to pass the mounting screw through the hole in the cooler into the screw hole on the mounting plate.  Get it started in the hole, but do not tighten it.  On the other side of the cooler do the same and snug down the screw.  Then go back to the other side and snug it down.  Neither screw will tighten completely.  You just want to feel some resistance.  

Next, I'll re-attach the fan to the heat sink and insert the fans power cable into the CPU fan header on the motherboard.
 
That's it.  The Freezer 7 Pro Rev.2 is installed.

Comparing the Temperatures after replacing the CPU cooler

We're back in Windows after installing the new CPU cooler.  I haven't changed any of the settings in the BIOS.  We want to compare the temperatures with the new cooler to what they were when the stock Intel cooler was installed.  I'll open RealTemp.  The CPU idle temperature is now  43c .  The idle temperature with the stock Intel cooler, with these frequency and voltage settings, was 62c.  That is a 19c decrease in temperature at idle.  Let's open Prime95 and compare the load temperatures by running the large FFts test.  After 10 minutes the temperature is 75c.  The load temp with the stock Intel cooler was 97c.  That is a 22c decrease in temperatures at load.  This is very good and will give us more thermal room to overclock the CPU even higher.

Overclocking to 3.8GHz

Let's try to get the CPU to 3.8GHz. A base clock of 190 x a multiplier of 20 gives us 3800 or 3.8GHz.  Once again the RAM, Uncore and QPI changed automatically. {reg}The RAM changed to 1143MHz which is well below the RAM's rated speed of 1333MHz.  The Uncore is 2286MHz which is twice the speed of the RAM and the QPI is at its lowest possible setting.  We want to see if these new frequency settings will work with the current voltage settings, so I won't make any changes to the voltages.  I'll make note of the settings, press F10 and Enter to save and exit.

Let's check RealTemp.  The idle temp is 44c.  I'll start Prime95 on the small FFts setting this time.  The small FFts setting puts more stress on the CPU.  The computer just restarted itself.  Prime95 had been running for 8 minutes and the temperature was 78c.

We need more voltage to make the system stable at 3.8GHz.  To make the overclock stable at 3.7GHz we increased the CPU PLL to 1.88v and the QPI DRAM voltage to 1.225v which didn't seem to effect the stability of the overclock.  The system still froze and restarted after those two increases.  It wasn't until we increased the CPU Voltage to 1.25v that the overclock became stable. The QPI DRAM voltage increase wasn't needed because of the low RAM and Uncore frequencies. Again, if you have 1600MHz RAM continue to follow along as if you have 1333MHz RAM. We will address 1600MHz RAM later in this lesson.  We're going to leave the CPU PLL and QPI DRAM voltage settings where they are and increase the CPU Voltage to 1.275v.

Let's check RealTemp.  The idle temp is 44c.  I'll start Prime95 on the small FFts setting.  Prime95 has been running for 15 minutes and the load temperature is 82c.  The overclock appears to be stable.  I'll close Prime95 and run BurnInTest on the CPU coverage setting for more confirmation of a stable overclock.  It passed.  I'll run 3dmark06 for further confirmation of stability and to get the CPU Score.  At 3.8GHz the CPU score in 3dmark6 is 7082.  So the CPU is stable at 3.8GHz.

Overclocking to 3.9GHz

Let's try to get the CPU to 3.9GHz. A base clock of 195 x a multiplier of 20 gives us 3900 or 3.9GHz.  The RAM, Uncore and QPI changed automatically. The RAM changed to 1173MHz which is fine.  The Uncore is 2346MHz which is twice the speed of the RAM and the QPI is at its lowest possible setting.  Once again, we want to see if these new frequency settings will work with the current voltage settings so I won't make any change to the voltages.  I'll make note of the settings, press F10 and Enter to save and exit.

Let's check RealTemp.  The idle temp is 44c.  I'll start Prime95 on the small FFts setting.  The computer just restarted itself.  Prime 95 had been running for 2 minutes and the temperature was around 80c.

I'm going to increase the CPU Voltage to 1.3v and test for stability.

Let's check RealTemp.  The idle temp is 45c.  I'll start Prime95 on the small FFts setting.  The computer just restarted itself.  Prime 95 had been running for 5 minutes and the temperature was 87c.

I'm going to increase the CPU Voltage to 1.325v and test for stability.

Let's check RealTemp.  The idle temp is 45c.  I'll start Prime95 on the small FFts setting.  Prime 95 has been running for 17 minutes and the temperature is 90c.  The overclock does seem stable.  I'll run BurnInTest on the CPU coverage setting for confirmation.  It passed.  I'll run 3dmark06 for further confirmation of a stable overclock and to get the CPU Score. The CPU score at 3.9GHz is 7163.  The overclock to 3.9GHz is stable.

However, the voltage increases required to make the overclock stable have pushed the CPU temperatures above 90c which is not recommended over extended periods.  We had to increase the CPU Voltage from 1.275v to 1.325v to achieve stability at 3.9GHz. That is a total increase of .05v. This is only .075v below the maximum safe voltage of 1.4v.

Overclocking to 4GHz

Let's try to get the CPU to run at 4GHz. A base clock of 200 x a multiplier of 20 gives us 4000 or 4GHz.  The RAM, Uncore and QPI changed automatically. The RAM changed to 1203MHz which is fine.  The Uncore is 2406MHz which is twice the speed of the RAM and the QPI is at its lowest possible setting. Taking into account the amount of voltage required to increase the frequency from 3.8GHz to 3.9GHz and keep the overclock stable we will need most of the remaining .075v to stabilize the overclock at 4GHz.  I'm going to be fairly aggressive and set the CPU Voltage to 1.39375v and test for stability.  This computer is in a closed desk.  To help out with the cooling I'm going to open the door to the desk  to allow cool air in.

Let's check RealTemp.  The idle temp is 40c.  I'll start Prime95 on the small FFts setting.  The computer hasn't restarted and Prime95 is still running, but one of the worker windows has stopped, saying there is an error. The CPU overclock is not stable with the current voltage settings. 

When I attempted to restart the computer to go into the BIOS, I got a blue screen and this is it.  On your computer when you are overclocking and it becomes unstable you may get a blue screen like this.  Usually on my computer it would freeze and restart itself.  Any kind of freeze, error message, blue screen are all signs of an unstable overclock.  I'll go ahead and restart and go back into the BIOS.

I'll up the CPU Voltage to 1.4v which is the maximum safe voltage according to Intel and test for stability. Let's check RealTemp.  The idle temp is 42c.  I'll start Prime95 on the small FFts setting. One of the cores is spiking to 100c and the CPU's safety mechanism is kicking in, lowering the multiplier, which is dropping the frequency to 3.9GHz.  The system may be stable with the 1.4v setting, but there is no way to tell.  We would need a water cooler to keep the temperatures down below 100c to know for sure.

We are out of thermal head room so we won't be able to overclock this CPU to 4GHz with any certainty of stability.

CPU Steppings and Revisions

This is one of the early Core i7s.  It was purchased about a month after they hit the street in late 2008.  If you have a more recent version of the Core i7 you may be able to overclock to 4GHz or higher.  I say a more recent version because all CPU designs go through steppings and revisions.  The more recent revision CPUs are usually easier to overclock because at any given speed the voltage required is lower for the CPU to run stably.  For example, an earlier revision CPU might need 1.4v to the CPU cores to run at 4GHz.  Whereas the latest, newer, revision CPU may only require 1.3v to run at that same frequency.

This is true for both Intel and AMD CPUs. To find the stepping and revision of your CPU go to CPUID.com and download CPUZ. Get the most recent exe, install it and run it. Our CPU's is stepping 4 and the revision C0/C1. You will often find the revision being referred to as the stepping by hardware reviewer and other users online.  Later numbers and letters are more recent.  D0 is newer than C0. D1 is newer than D0. We will go more into CPU steppings and revisions in the 2010 Home PC Builder videos.  Suffice it to say that a CPU with a more recent stepping and revision is almost always better at overclocking.  The Core i5 CPUs which are very closely based on the more recent Core i7 design may overclock easier as well.

1600MHz RAM

If you actually have 1600MHz RAM and have been following along to find your maximum CPU core overclock, which may be lower or higher than ours, you can go into the BIOS and move the RAM speed up a notch. If your base clock is currently 195, the next notch up will be 1560MHz which is just below the rated speed of your RAM. If your base clock is currently 200, the next notch up will be 1604MHz which is a very small overclock of the RAM and should not be an issue.  When you make that change the Uncore frequency will jump from it's current speed of 2406MHz to 3208MHz.  This is a sizable overclock that will almost certainly introduce instability.  This is when you do need to increase the QPI DRAM voltage to stabilize this new overclock.  Start by increasing the QPI DRAM Voltage to 1.3v and use Prime95 on both Blend and small FFts settings along with the RAM and CPU Coverage tests in BurnInTest to check for stability.  If the overclock is stable you can decrease the QPI DRAM voltage one notch at a time, testing for stability with each decrease, until you find the minimum voltage that produces a stable overclock.  If the overclock is not stable with the QPI at 1.3v you can increase the voltage one notch at a time and test for stability to find the minimum voltage that produces a stable overclock.  

Finalizing the Overclock

Once you have your final maximum stable settings you need to think about a few things.  Did you have to increase the voltage a little too much to get that last .1GHz speed improvement? Are the temperatures a little above the recommended levels?  Is that .1GHz speed improvement worth shaving off a year of your CPU's life or having your CPU fan spin too fast making your otherwise quiet computer a little too noisy?

In my case I'm going to lower the CPU speed down to 3.7GHz.  It required only a .05v increase of the CPU Voltage from the stock setting to run stable at that speed and with the new cooler, the load temps were in the low 70c.

Overclocking the RAM

Our RAM is rated to run at 1333MHz.  I would like to see if we can get it to run even faster than we did in Lesson 4.  In Lesson 4 we had the base clock set to 175, which gave us an overclocked RAM speed of 1403MHz which was stable.  With our current base clock of 185 the RAM speed is now 1103MHz.  The next speed up is 1483MHz.  I'll make that change and test for stability.

We haven't changed the CPU overclock so the temperatures should not change.  I'm going to run Prime95 on the Blend setting to test the RAM and I'm also going to run BurnInTest on the RAM setting at the same time.  This will put a lot of stress on the RAM.  It passed the RAM test and Prime95 has been running for 15 minutes.  The RAM overclock is stable.

The next step up in RAM speed is 1850MHz which would certainly fail so I'm not going to try. If the tests failed or the system restarted with the RAM set to 1483MHz there are two things I could try.  The first would be to increase the memory voltage.  You need to be careful here and not push it too far.  I checked with the manufacturer and my memory can take up to 1.6v.  I would then test for stability.  If the tests still failed I could increase the memory timings using the DRAM timings settings.    At the top the default timings for my memory are shown.  With the settings at Auto the times are at the default settings.   The first 4 are the ones that can make a difference in stability.  I would change the first 3 to 9ns and the 4th to 25ns.  This will give the memory more time to make it's reads and writes.  If the tests still failed after these settings changes I would just have to set them back to default and the RAM voltage as well and set the RAM speed back to 1113MHz.  Any further increase in the timing would slow the RAM down too much and make the speed increase pointless.  Our RAM did work with all the default settings so I will leave it set at 1483MHz.

Turning the power saving features back on

The only other thing to do is turn back on the power saving features.  I'll enable the C1E Support, SpeedStep and C-State.  I'll save and go back to Windows.  In RealTemp we can see that when the CPU is at idle, or very lite load, the CPU multiplier is lowered, making the CPU frequency lower.  If we use Prime95 to give the CPU something to do, the multiplier jumps back up to 20, making the CPU run at 3.7GHz, giving us full performance.  If we stop Prime95 the multiplier immediately lowers into power saving mode, lowering the energy used, lowering your electricity bill and prolonging the life of your CPU.

I think that's it.  If there is anything about these lessons you didn't understand, need to know more about or if you think I'm just plain wrong about something please email me at This e-mail address is being protected from spambots. You need JavaScript enabled to view it  


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