Lesson 03 – Overclocking related settings in the BIOS


In this lesson we are going to cover all of the overclocking related settings in the BIOS.  Then we will set all of the frequency, multiplier and voltage settings to default so we are in full control.  Last we will learn how to save the BIOS settings to a profile we can reload at a later time.

BIOS Information Screen

I’ve just powered on the computer and before we enter the BIOS I need to point something out.  This is what is generally called a BIOS information screen.  The information goes by very quickly so I’ve pressed the Pause-Break key to pause it.  Pressing any other key will un-pause it.  It shows the CPU model, the amount and speed of the memory and lots of other information that is useful when overclocking. This BIOS information screen is a little less useful than most, most will show the actual speed the CPU and RAM are running at.  Just about all motherboard makers cover this information screen up with a logo screen.  There is a key to press, typically Tab to hide the logo screen and show this information screen but you have to hit Tab every time you want to look and a lot of the time the information you need is gone before the Tab command takes effect.  The first thing we’re going to do in the BIOS is make sure that logo screen is turned off.  I’ll press any key to continue and on this computer I need to press Delete to enter the BIOS setup.  On some computers it’s the F2 key to enter the BIOS setup.

This is the BIOS main menu. It has several menu choices at the top that take you to different sections of the BIOS.  Here’s another common main menu layout with it’s sections laid out on one common page.  Just about every motherboard maker uses one of these two layouts.  These videos are concentrating on overclocking so we’re not going to get into most of these options.  The Home PC Builder videos have a video that covers the BIOS in general and it’s Lesson 1 of the Computer Setup Lessons.

Disabling the Logo Screen

The logo screen setting in this BIOS is under Advanced BIOS Features, called Full Screen Logo Show and it is Disabled so it won’t come up.  On other BIOSs it can be found under Boot and Boot Settings Configuration.  The default is Enabled.  You can select it and disable it.

Finding the Overclocking Settings

I’ll hit esc on the keyboard to get back to the main menu.  In this BIOS all of the overclocking related settings are in the MB Intelligent Tweaker or (MIT).  Most BIOS’s have a section like this.  Asus calls theirs the AI Tweaker. You can find EVGA’s version under Frequency/Voltage Control and MSI calls theirs Cell.  If your motherboard doesn’t have a section like this or you can’t find the options you see here in your BIOS then you won’t be able to overclock the CPU.  This is fairly rare these days but just to be on the safe side, before you buy a motherboard go to the makers website, download the motherboard manual and look for these settings.

Disabling Power Saving Features

Next we’re going to find and disable the power saving features Quiet and Cool and C1E support so we have control over the speed of the CPU.  In this BIOS the power saving features are under the Advanced BIOS Features.  We’ll make sure C1E support is disabled. We can press enter to disable C1E support or use the page up and down buttons to toggle through the options. Quiet and Cool is disabled.

Setting Fan Speeds to Maximum

Next we need to make sure the CPU fan and system fan is always running at 100% speed.  In this BIOS and in most other BIOSs the fan speed settings are under PC Health.  If we scroll down we find CPU Smart Fan Control. By default it is enabled.  We’re going to hit enter and disable it. A little lower on the list we find System Smart Fan Control. I’ll use the page up and down keys to disable it.


Overview of Overclocking Settings

I’ll hit esc to get back to the main menu.  Lets go take at look at the overclocking related settings. I’m just going to cover the settings we will be changing.  The others are fine at their defaults. The CPU clock Ratio is the CPU multiplier. CPU NorthBridge Frequency is the multiplier used to control the CPU cache and Memory Controller.  CPU Host Clock Control is the reference clock speed.  The HT Link Frequency controls the speed the HyperTransport bus runs at. Set Memory Clock allows us to change the memory multiplier.  DRAM Configuration gives us the ability to change the memory timings.  That is how long the memory waits between operations or it’s CAS settings you’ll remember from memory component lesson in the Home PC Builder videos.  We can also set the reference clock speed and the memory multiplier here.  These settings are mirrors of the ones on the main MIT screen.  We’ll hit esc to go back to the main MIT. Next on the list is System Voltage Control which lets us change the voltage for some key components.  The ones we’re interested in are the DRAM voltage which controls the amount of voltage going to the memory, CPU NB voltage which controls the voltage going to the CPU cache and onboard memory controller and the CPU Voltage Control which controls the voltage going the the CPU cores.
Manually change all Overclockings settings to default

 Right now all of the options are set to Auto meaning the motherboard has control of all the frequencies, multipliers and voltages.  We want to take that control from the motherboard and set all of options manually so we know what frequencies, multipliers and voltages are being used for each component. Lets scroll back up to the top. With the settings at auto the motherboard is getting the speed and voltage information from the CPU and RAM.  If you highlight CPU Clock Ratio and hit enter we get a list of multpliers to choose from.  I’ll hit esc.  You’ll remember that the CPU speed which here is 3200MHz or 3.2GHz is derived from the ref clock times a multiplier.  If we work back words and divide 3200 by 200 we get 16. So the multiplier being used is 16x.  We can go in and manually set that multiplier and the CPU speed is still 3200MHz.  We do the same for the CPU NorthBridge Frequency.  2000 divided by 200 is 10.  We’ll set the reference clock to 200 manually as well.  The HT Link Frequency is 2000 and again 2000 divided by ref clock of 200MHz gives us a multiplier of 10x.
The memory clock is automatically set to 1333MHz, but our RAM is actually capable of running at 1600MHz. It’s getting the 1333MHz speed from the multiplier of 6.66 x the ref clock of 200.  This is fairly common for the BIOS to set the RAM speed to the next slowest available speed, just to make sure the system will boot up.  I’ll change it to manual and increase the multiplier to 8x.  8 times the ref clock which is 200MHz gives us 1600MHz.  I’ll go into the DRAM Configuration and set the CAS timings manually as well.  Change the DDR3 Timing Items to manual and I know by looking at the RAMs specs that the timings should be set to 9 9 9 and 24.  You will need to get your RAMs CAS timing settings from your RAM. If you have 1333MHz RAM set the multiplier accordingly.
We’ll leave the rest of the settings alone and hit esc to go back to the main MIT screen. For the System voltage control I’m going to change it to manual.  This sets all of the options below to Normal which means default.  I am getting a flashing message above that the System Voltage is NOT Optimized!  What this means is that the motherboard does not have control to change the voltages automatically.  This is what we want.  We want to be in full control of all the variables while overclocking.  So we have all of the controls set manually to their default values.  This is where we need them so we can begin overclocking.  Before we do that it’s a good idea to save these settings.

Saving Settings to a Profile
We could press F10 to save and exit but it’s best to save these permanently so after we make changes to the settings and want to get back to the way they are now we can quickly load them.  Most BIOS’s have a configuration saving feature.  On this BIOS it is on the main BIOS menu.  I’ll hit esc and down at the bottom right I see I can hit F11 to Save CMOS to BIOS. I’ll hit F11 and there are 10 profiles we can save to.  I’ll call this one default.  Now if I hit esc to go back and lets say go into the MIT and change the CPU multiplier from 16x to 15x. Esc and press F12.  Load the default settings and go back to the MIT, the setting is restored to 16x.
This will come in very useful as we do various tests while overclock.  Once we have a overclocking result we like we can save it and always have it to come back to.
Next in Lesson 4 we will get started overclocking by finding our motherboards maximum stable reference clock speed.