Disclaimer: The following information is passed on with best intentions but I cannot guarantee that there is no risk involved with changing your bios revision or overclocking your system. You do so at your own risk. All of this comes from successfully overclocking my Q6600 G0 stepping to 3.0Ghz on my Asus P5N-E.
1 - How to flash your Asus P5N-E
Despite what you may read on other forums, it is possible to install any bios version on the P5N-E when you require. I have had 0703 -> 0803 -> 0608 -> 0901 -> 0608 throughout my time with the P5N-E. First off forget about using the Asus Update tool in Windows as it will probably not let you go down to a previous bios than the one you currently use if required. I prefer to create a bootable CD image as it allows me to store multiple bios' on the disk and verify that the copy has worked correctly after burning the disk because the last thing you want is to have a bios partially copied to a USB stick etc and then to flash your system.
First off go to the Asus P5N-E
main webpage and download all of the bios revisions you want to a folder on your machine. Extract the .bin (bios files) from the zips into the folder. Download as many or as little as you want but I would recommend getting 0608, 0703, 0803 and 0901. Next download the Asus Awdflash Flash utility
and extract the awdflash.exe into the same folder as the ####.bin files. And finally, download a copy of Flash CD
and unzip the FlashCD.iso into the same folder.
Now you need to open the ISO image and add the bios files and AWDFLASH.exe into the existing list of files. I use UltraISO
as its real easy and the free trial should allow you to do this task quickly. Once you have added the files to the ISO you can save it for use later and burn with your favourite CD burning software or burn with the included option within UltraISO. You should now have a bootable CD with all of the required files to flash your P5N-E
Boot the computer up with the CD set as the primary boot option in the bios. Give it a minute or so and you will be at an old dos prompt and if you read the passage above the prompt it will say what drive letter has been assigned to your CD-Rom device. In my case it says R:\\ so I type in R: and press return to get to the R:\\ prompt. Now I'm going to flash my P5N-E's bios by typing in the following:
awdflash ####.bin /f
#### is the bios revision number we downloaded earlier and are planning to use and the /f tells the flash utility to force the upgrade/downgrade. Pressing return/enter will bring you to a screen like this one
prompting you to save the existing bios. Enter N to say no to this as you do not need to save it and will be unable to save to the CD anyway. Next you will be prompted to start the flash but entering Y. Doing so will start the flash process and show you a screen not unlike this one:
The flash should take about a minute or two to complete and will prompt you to press F1 to reboot. This will restart the computer with a black screen for a short time before displaying a message says something like its updating CPU Checksum and then shows the Asus splash screen.
2 - First Overclock
Over clocking your system is not straightforward and what might be good for me might not work for you. To give you a little bit of history about my overclock, I initially went straight from default settings to manual and set the system to unlinked with QDR 1333 and DDR 667. Immediately the system failed to boot and no matter what I tried it would either hang at windows loading, hang at the bios screen or just not display anything on the screen at all. I upgraded the bios to v0803 and tried again but got the same results. However, upon reading a few forums I found that people were having more joy with the 0608 bios more so than any other so I put everything back to default and downgraded from 0803 to 0608. Again I set up manual settings with Unlinked QDR 1333 and DDR 667 and everything else was left as default. Sure enough the PC booted straight into Windows at 3.0GHz right away. My motherboard bundle came with the CPU installed with a Thermaltake TR2-M13 SE LGA775 fan and temps were around the low to mid forties idle and high fifties under load. Checking CPU-Z I could see that the motherboard had set the memory timings on my bundled 4Gb Elixir
ram to 5,5,5,18,2T. I was able to play my games etc without any problems but I wanted more.
3- Current Overclock
Given that I had it running well @ 3.0GHz before, I decided to see if I could push it and tried all kinds of other settings all the way up to 3.15GHz with various levels of success. Ultimately it wasn't as stable as I wanted and there seemed to be a hole after 1350 QDR that made things a little unreliable so I've gone back to basics.
It was always my plan to replace the rubbish ram that came with my motherboard bundle so I replaced the original 4GB Elixir DDR2 for Corsair Dominator TWIN2X2048-8500C5D performance ram. I also got rid of the awful northbridge heatsink and replaced it with a Thermaltake Extreme Spirit II Chip Cooler CL-C0034 and added a Akasa Chipset Cooler AK-210 to the southbridge that just about covers it all and allows for the second GPU.
My plan at the moment is to burn it in for a few weeks stable at 3.0GHz and then eek out what I can slowly from there as I was probably taking to big a jump each time afterwards. Incidentally, I tried the 0901 bios and had the same problem as the 0703 and 0803 where it wouldn't even get past the bios boot so went straight back to 0608.
My current setup is as follows.
Some people have PM'd me to say they are a little lost when booting the CD up and finding their CD drive letter.
As you can see from the image above, I have created the CD using FlashCD and booted up the PC to the dos prompt. Where it says "Drive R: = Driver Banana Unit 0" this signifies that drive R has been created for my CD Rom device. Entering R:\\ takes me to the CD device and allows me to run the flash code. Your machine may not say drive R is your CD Rom device so take a look at this path on your machine to find out which one it has mapped and use that drive letter instead.
I hope this helps some people out and good luck with your overclock.