..

So, set everything back to highest FSB/multi/voltages etc as found out earlier on, and start tweaking that bandwidth down the list until you find the fastest it'll achieve.

Remember to run a Sandra memory bench after each tweak to burn in the memory as you go and to check the bandwidth. Write your scores down as you go, or better still get a screen-capture and name it something to remind you of what it is etc. Combine all of this lot together to get your system to its MAX. When stability goes flaky, start try dropping the FSB slightly to allow you to raise the bandwidth tweaks, as often better timings will increase your scores better than a higher FSB... Macci once pointed out to me that his memory bandwidth scores at 166Mhz floored mine at 200Mhz, and that's when I learned that the timings were everything for good 3DMarkscores.

You'll find a point where Sandra will run but 3DMark won't. Make the decision, what are you trying to achieve. Is the overclock just so you can have a faster PC, or are you using your overclocking skills to gain you a reputation and earn respect of others? If the answer is the latter, then it's irrelevant. You'll spend one day getting the best CPU Mhz you can. Another day devoted to getting a screencap of the best Mem Bandwidth you can. Another day getting the highest 3DMark score you can, another day getting the fastest HardDrive transfer rates you can.... screencaps of the lot, post 'm in the forums, let the fans worship & adore you (until they beat you!!). Hardcore overclockers spend weeks devoted to bettering each individual score, and then when they've got the best scores they can, they sell off that component and try to find one that'll do even better... On and on we go...



Added note...

Barton CPUs
Get a damn site hotter than Thoroughbred CPUs, and need more voltage to get good overclocks. Average top out on Prometeia / nVentiv Mk II - 2.7Ghz for average stepping. 3Ghz for super stepping. You won't get as high as TOTAL overclock out of a Barton as you would out of (for example) a Thoroughbred 1700+ DLT3C, however, a Barton at 2.4Ghz can match and beat a Thoroughbred at 2.6Ghz... usually....

2500+ is the most popular choice. These hit 2.6/2.7Ghz with about 2.1v on a Prometeia. On water expect to top out at around 2.5Ghz or 2.6Ghz... They'll do 2.3Ghz with ease at 1.9v usually.


Thoroughbred CPUs

Steppings count. Look for CPUs with a DLT3C JIUHB stepping (usually XP1700, 1800 & 1900 CPUs). The 1700+ CPUs can go to 3Ghz if you have a REALLY good one, or 2.8Ghz if you have an average one. These chips run at a lower default voltage, so run cooler, and need less juice to go fast.... so when you give em LOTS of juice, they go REALLY fast! On NF7 boards, these chips tend to top out on voltage... they rarely post at 2v without setting sirens and alarms off, but that's down to the way the board handles power.
Average OC? On air, about 2.4Ghz, on water about 2.6Ghz, on pelts around 2.7Ghz, on Promi about 2.8Ghz.



Memory ratings

Most of you have good memory, but also, a lot of you have it for bragging rights and don't put it to use. If you have anything above PC2700 speeds, and you DON'T have a Barton 3000+ or 3200+, and you're not overclocking, then your ram is merely an attempted willy-extension that works in reverse to those in the know, and actually halfs the size of your willy. :-)


Background - CPU FSBs

Athlon XP Palomino and Thoroughbred CPUs - default FSB 133 (PC2100)
Athlon XP Barton CPUs - default FSB 166 (PC2700) or 200 (PC3200)

So, unless you set your ram to run at its rated speed (thus overclocking the FSB of your CPU usually) then you've forked out for summat pointless... here's what FSB you should be running at...

PC2100 - 133FSB (DDR266)
PC2700 - 166FSB (DDR333)
PC3200 - 200FSB (DDR400 for AMD, QDR800 for INTEL)
PC3500 - 217FSB (DDR433)
PC3700 - 233FSB (DDR466)
PC4000 - 250FSB (DDR500)
PC4200 - 266FSB (DDR533)

Now, anything ABOVE 3500 tends to work out to be a duff buy for AMD users. Once you hit 3700, default rated CAS timings get ridiculously slow - usually Cas3, and as soon as you try to make them faster - Cas2 - you can't achieve rated FSB, let alone overclocked FSB... For AMD users it is much harder to run ultrafast FSBs like the P4 boys do, so we rely more on Ram timings to keep us on their heels.... 3500 and below is generally rated at Cas2 by default, and 9/10 times will tighten up to 11-2-2-2 on an nForce2 board without problems.

Most AMD Boards and processors will struggle to run at 233FSB anyways, therefore 3700 is a bit pointless... and when you DO get it up there, with the slower CAS timings that you'll need you'll find that running at 217FSB with 3500 at a faster CAS Timing actually offers much better performance.

BUYING memory

we've just gone through which is best to buy.... anything at 3500 and below for AMD users. What you want to be looking for is the highest rated speed at the lowest rated CAS Timings.... i.e.: PC3500 rated at 6-3-3-2 is a better buy than PC3500 rated at 7-3-3-2. By dropping the 6-3-3-2 stick's timings to 7-3-3-2, you're practically guaranteeing another 5Mhz on top of rated speeds for that ram. The best stuff to find is ram rated at 5-3-3-2 or 5-2-2-2 at 1T Command. This was around in the days of the KT333 chipset, where there were a lot more options available to you in the bios for tweaking your ram. The nForce2 chipset, with its much more aggressive approach to memory, meant that suppliers had to slow down their CAS ratings to get their memory to work properly with the chipset and its Dual Channel Architecture, hence why we see more and more memory coming onto the market rated at 8-4-4-2.


//Marci


check the next page for an overview of popular Overclocking Tools