If your board has a separate adjustment for your memory voltage, you will want to make sure that you use it! 2.5v is default for DDR and I will usually go as high as 2.9v of 3v when I am really pushing things to it's limits. Also usually with a little bit of added voltage your RAM will be able to run with some more tweaks turned on at speeds that they'd usually be unstable at.

Of course, you will want to start with very high quality memory. For the highest speeds WITH tweaks turned on with your RAM, I'm going to have to say give Mushkin a shot. Often times, OCZ memory will achieve higher speeds but they tend to crap out a lot quicker when you turn some tweaks on. Crucial is also a very good place to get high quality RAM from. Some of the best overclocking RAM I've ever seen is Hynix 7ns chips.

Time to start cranking

First of all, undo all tweaks on your RAM. This is a necessity to try and figure out how fast the rest of your parts can go. Make sure your RAM is set for cas 2.5 (3 if your an SDR guy) to make this easy on you load the fail safe defaults for your board.

Also when you're starting, leave your voltages at default at first, and slowly bring them up after your system becomes unstable.

If you can lower the multiplier on your CPU drop it down as low as you possibly can. If not then you'll have to increase your Vcore as the speeds increase. Go up very slowly, and only try a few Mhz increase at a time. Make sure your system has an installation of windows on it, and let it load all the way into windows and then run some kind of a RAM benchmark. Sandra (SiSoft Sandra Marks)will work just fine. Keep going higher and higher until your system doesn't load windows. At this point, it is time to increase voltages slightly. If your PCI bus is running below 40Mhz then you won't need to touch your IO, but if your CPU is running overclocked then increase the voltage to your CPU a little bit at a time. If that doesn't stabilize your system, or your CPU is not running out of spec, then the most likely culprit is your RAM crapping out on you! If that is the case then increase your Vmem a little bit.

If the voltage increases fix you up and your system is stable again then.... GO FURTHER! HAHAHAH this time increase your bus speed 1Mhz at a time or the smallest amount possible if your board doesn't have 1Mhz increments. Do this until you get the highest speed you can with the level of voltage that you're comfortable with. Once you've found your top speed, then start working on turning some tweaks on and slowly backing down the FSB a little bit at a time in order to run with at least a few RAM tweaks on. Generally what I do is I use Sandra as a memory bandwidth benchmark and a lot of times a lower bus speed with a tweak or two turned on will outperform an insanely high bus speed.

Play with some settings for a while until you get the maximum bandwidth possible. If your CPU is unlocked, then you can try increasing the multiplier now. You can either bring the processor up to it's default speed or of course overclock it ;)

The End

These are the principles that I used to pull this kind of speed on my Abit KR7A. My PCI bus was in fact running at 50Mhz even which is quite a bit beyond the 33Mhz spec. Due to the 4:2:1 divider I was limited by that. I feel this board would be capable of going faster if only it had the divider support. I'm currently sampling some new boards and will continue to strive for the highest bus speed possible and of course tweaking things out to get the most performance possible ;)

I will be working on an extensive memory timing guide and tweaking guide very soon. I have a few more articles I want to finish up before I start on another big project.

Stay tuned as we bring you more good stuff as we can. If you have any comments or questions about this article I have designated a thread in the forum to this topic.