Given all the recent threads in relation to overclocking on the P5K-E and similar I thought I would write a guide to explain the basics to overclocking on this motherboard, this should also hold true in part to overclocking on other similar Asus boards such as the P5K-C, P5K – Premium, etc… If you are not using the P5K-E however you may notice that there are some differences in your BIOS but the general principles should still hold true. Before I start there is a wealth of information on these forums in regards to overclocking, the Q6600 and this motherboard (and similar) and therefore the following threads are certainly worth investigating and should provide you with answers to a lot of your questions! Beginners Guide to Overclocking: http://forums.overclockers.co.uk/showthread.php?t=17612922 READ THIS THREAD! This will explain all of the basics that you need to know, I will be discussing late the ins and outs of overclocking on the Asus P5K-E but you should make sure that you have a general understanding of what overclocking is and how it is achieved. Intel Quad Core Database: http://forums.overclockers.co.uk/showthread.php?t=17779323 Again this thread details the settings, clock speeds and outcomes of a lot of clocks with the Q6600 both B3 and G0 Stepping… It is certainly worth a good read through and will give you an understanding of the sort of settings you will require to achieve you clock Official Asus P5K Thread: http://forums.overclockers.co.uk/showthread.php?t=17731841 Again this thread is a gold mine of information in relation to the P5K boards, giving links to where you can download various BIOS for your motherboard and also links to the spec of your board, thread also contains a wealth of information from overclockers and their experience with the board. Overclocking A Very Brief Round Up Hopefully you now have an understanding of what overclocking is and how it is achieved, I know when I first started all the numbers and names didn’t make a huge amount of sense until I started to have a play around with the BIOS but to put it simply the clockspeed of your Q6600 is based on two factors your motherboards Front-Side Bus Speed (FSB) and the CPU ratio… for example with a FSB of 400 and CPU Ratio of 8 you will achieve a clockspeed of 3200mhz. (400*8) The second important factor when overclocking is the speed that your RAM runs at, again when I first started I was a little confused when people talk about RAM ratios and dividers etc… but again simplified your RAM speed is based on the FSB of the motherboard given the P5K-E supports DDR2 memory you can calculate the speed that you are running you RAM at by simply doing FSB * 2 so for example on our above FSB of 400 the RAM would be run at 400*2 or 800mhz which is the standard speed for 6400 RAM. Getting to know your ASUS P5K-E Ok to get to the BIOS you need to press [Del] as the board is posting... All of the overclocking options on this board can be found in one menu option in the BIOS so lets go take a look! Go to the [Advanced] menu and then go down to the first option [Jumper Free Configuration] If its your first time in this menu you will see that everything is set to Auto to enable an overclock we must set a number of these options to manual, so go through the menus and set the below to Manual, you will notice that as you set these to manual you get more options appear. [AI Overclocking] [CPU Ratio Control] [DRAM Frequency] [DRAM Timing Control] With everything set to manual we have all the options that we need to setup an overclock, the options that are going to be of interest are: [Ratio CMOS Setting] – this is the CPU Ratio that was discussed earlier you can enter a number from 6 – 9 (default 9) in here and it will multiply this by the FSB to calculate your clock [FSB Frequency] – here you set the FSB you want to run the motherboard at, the default to run your Q6600 at stock is 266 (assuming a *9 CPU Ratio) [PCI-E Frequency] – I always set this to 101, some people use 100 or 105 but in general take it off Auto. [DRAM Command Rate] – Set this to your manufactures recommendations 1T or 2T [DRAM Timing Controls] – Set these to your manufactures recommendations, generally only the first four are manually set as they make the most difference to performance, the rest can be set or left on Auto [CPU Voltage] – this is often referred to as vcore, for now we are going to set this to 1.300v which should be plenty for you to boot to windows at stock, all Q6600 CPU are slightly different and some need more volts than others but 1.300v should be enough for even the hungriest! [DRAM Voltage] - Set this to the voltage recommended by the manufacture, note RAM is far more sensitive to voltage than you CPU and you should be very careful not to overvolt that RAM as this can cause damage [CPU Voltage Dampener] Also Called [Loadline Calibration] – THIS IS YOUR FRIEND! Whilst reading through the forums you have more than likely come across the terms vdrop and vdroop, this is where the vcore in the BIOS changes as the CPU is put through different levels of stress… this setting will keep your vcore levels nearer those that you set in the BIOS eliminating a lot of the vdrop and vdroop problems. So make sure you set this to Enabled [Northbridge Voltage] - For now keep this on Auto, if you are running 4 sticks of RAM you may want to set this to 1.45v but in general shouldn’t cause a problem leaving this on Auto Lets Get Clocking! Before you start firstly make sure that you have Prime95 and Coretemp installed and that you have round off checking enabled in the advanced menu of Prime95. These are essential to check the stability of the clock and keep an eye on your temperatures, if at any stage your core temperatures go above 70c then stop Prime95…(you can run higher than 70c if you like! But 70c is my limit on temperatures if you feel comfortable going higher that is of course your choice!) A couple of things to consider when overclocking is that if a clock fails you want to make sure that you understand why, so before starting an overclock loosen all of your RAM timings so if you have C4 RAM rated at 4-4-4-12 then set it to 5-5-5-23 this will ensure that your ram is not overstressed… this should also ensure to a point that if the RAM is running faster than it is rated that it should work ok! (to a point) I would suggest that you at this point follow the beginners guide to overclocking, firstly going up through the FSB of the motherboard to find where the board has “FSB holes” i.e. where it isn’t stable, and then deciding on the clock speed that you wish to achieve and work your way up to it… Alternatively the setting below should get you to 3200Mhz with few problems (fingers crossed) [Ratio CMOS Setting] = 8 [FSB Frequency] = 400 [DRAM Timings] should be loosened out as explained about – also check that the RAM is running at 800Mhz if not adjust [CPU Voltage] = 1.325v Set these and save them to Profile 1 [Tools -> Asus OC Profiles -> Save To Profile 1] Let you machine load up into windows… if it doesn’t load then go back into the BIOS and increase the vcore but 1.325 should be plenty! Start up Prime95 and Coretemp and let it run for 15 mins keeping an eye on your temperatures… If it last 15 mins then go back into the BIOS and lower the CPU Voltage by 1 notch and retest, do this until the Prime95 fails within the first 15 mins… once it fails increase the vcore by 1 notch and run Prime95 for a good few hours, if it fails increase the vcore by another notch until it passes at least 3 – 4 hours… This should give you a stable platform to build your clock from or a nice 600Mhz overclock to your Q6600 Once you are happy with your clock and it is stable, reduce your RAM timmings back down towards the Manufactures recommend settings and run Blend Tests In Prime95 to ensure stability EDIT 1: What BIOS to use? Really in my mind after playing around today with 0806, 0906, etc they are utter rubbish! Best bet by far is 0602... I could not get higher that 3700mhz on either 0806 and 0906 and both under volted the vcore by .1v i.e. 1.5v BIOS came out as 1.4v less vdrop and vdroop (which was huge!) so no 0602 all the way... If you want to reflash your BIOS I have always used the windows prog and never had a problem the later version of this prog do not let you roll back but download this version: "ftp://ftp.asus.com.tw/pub/ASUS/mb/fl...sUpdt61002.zip" - right click save target works for me or google search for Asus Update v6.10.20 should find you a download as well Load it up and go into options and you have an tick box that will let you install older version of BIOS... then just flash and enjoy you new super nice, super stable BIOS Edit 2: Advanced Overclocking Options Ok following some feedback I have decided to go over some of the more "advanced" overclocking options avaliable in the BIOS and some basic options that I didnt cover initially. [FSB To Northbridge Strap] - This option basically determines what memory dividers are avaliable, as you increase the speed of the strap you will have to reselect the memory divider that best adjusts you DRAM Frequency. Generally I would set this to 333mhz as it is considered the most stable strap to overclock on. It is also worth considering that higher FSB Straps tend to allow for greater base FSB speeds to be achieved Again this is a "safe" setting as far as BIOS settings go, may cause some instability at higher clocks if you decrease the FSB-Strap Speed [AI Transaction Booster] - Has a fancy name but is actually pretty important If you have used a program like memset this is whats known as the "performance level" of the RAM. Basically has a direct effect on memory read performance and also some effect on the memory latency. Once you have achieved a stable overclock you want to try and get the boost level as high as possible. This wont damage the machine in any way, but will cause serious instability when you boost it to much [CPU / Northbridge Reference Voltages] - Basically used by the CPU/NB to determine if a signal is a 1 or 0, also pretty essential as FSB speed increase over 450FSB, these are reference only so will not damage your CPU/NB best to play around with once your clock starts to become unstable at high FSB speeds [CPU PPL Voltage] **WARNING** This can damage your hardware Ok big red writing out of the way in all seriousness you play with this one at your own risk Ok as I understand it acts as a Link between the CPU and FSB and is important for very high FSB.. Personally I would not run @ over 1.7v for benching but I know people go higher for all other instances I leave this on auto..