I got a asus a8n-sli deluxe, 3200+ (90nm), 1gb pny pc3500 (saving for some ocz) 6600GT, 420watt thermaltake powersupply. I want to start oc'ing now that i know my system is stable. Where should i start? thanks guys
Start by flashing to the latest bios. It makes all the difference in the world.
First of all, you need to check the max of the cpu. Just use the highest multi which is 10, drop the LDT to 3X. Set the timings to cas 2.5, the rest on auto for now. If you have good cooling, don't be afraid to use up to 1.6 vcore. More if you have watercooling.
You may also want to set your memory divider low to 166MHz (5/6) or lower to ensure you have your ram out of the question when looking for your maximum cpu clock. Once you have those parameters set (Mackanz hit all the relevant ones), just start upping the HTT/Bus speed 10-20MHz a shot, and see what you can get. Your chip will likely start topping out somewhere in the ~2.5-2.6GHz range, at which time you'll have to start kicking up the vcore for stability. I believe your ASUS board should allow for 1.65Vcore tops, so save yourself the trouble and set it there right away. That voltage should be safe for pretty much any decent air-cooling, including the retail HSF which is actually pretty good. Some lucky individuals have managed 2.7+ on those winchesters, good luck! and let us know how you fair!
LDT is a confusing subject sometimes, but it is essentially the final multiplier used to determine your total HTT clock.
For example, a 3200+ 754 proc..
200MHz (bus/mem clock) x 4 (default LDT) = 800MHz .. then you multiply that by two, for 1600MHz which is the default HTT speed. The 1600MHz HTT clock is basically the bandwidth the cpu has to communicate with other components on the HTT, such as the memory controller. Since the memory uses only a fraction of the avaliable HTT bandwidth, raising the LDT multiplier almost always results in a zero performance gain. The trick with overclocking is that when raising your bus clock/1:1 mem clock, you also increase your HTT. When overclocking, you have to find your LDT sweet spot. Too high or too low will usually result in instabilities. Your best bet is to find an overall HTT speed comparable to the default. (in the range of 1400MHz - 1800MHz). When cranking up the bus, an LDT of 3x is usually a safe bet.
I'm not too familiar with the 939 platform, but I believe some 939 procs use a default LDT of 5x instead of 4x like the 754s.
I used to have a good link that explained LDT well, I'll see if I can find it..
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First of all, you need to check the max of the cpu. Just use the highest multi which is 10, drop the LDT to 3X. Set the timings to cas 2.5, the rest on auto for now. If you have good cooling, don't be afraid to use up to 1.6 vcore. More if you have watercooling.
For example, a 3200+ 754 proc..
200MHz (bus/mem clock) x 4 (default LDT) = 800MHz .. then you multiply that by two, for 1600MHz which is the default HTT speed. The 1600MHz HTT clock is basically the bandwidth the cpu has to communicate with other components on the HTT, such as the memory controller. Since the memory uses only a fraction of the avaliable HTT bandwidth, raising the LDT multiplier almost always results in a zero performance gain. The trick with overclocking is that when raising your bus clock/1:1 mem clock, you also increase your HTT. When overclocking, you have to find your LDT sweet spot. Too high or too low will usually result in instabilities. Your best bet is to find an overall HTT speed comparable to the default. (in the range of 1400MHz - 1800MHz). When cranking up the bus, an LDT of 3x is usually a safe bet.
I'm not too familiar with the 939 platform, but I believe some 939 procs use a default LDT of 5x instead of 4x like the 754s.
I used to have a good link that explained LDT well, I'll see if I can find it..