View Single Post Aug 7, 2008, 09:45 PM #106 Psychlone AMD Overclocking Guru   Join Date: Apr 2003 Location: Searching for the airspeed velocity of an unladen swallow... Posts: 238   Now, we're off to a running start: First of all, here's AMD's overclocking equation: (You're going to want to print all this out - this is easy once you know it... I promise!) (CPU Multiplier * HTT) = CPU Frequency (CPU Multiplier / (memory divider) ) = Divisor Ratio (ALWAYS ROUND UP TO THE NEXT INTEGER!!!) (CPU Frequency / Divisor Ratio) = RAM MHz (* 2 = DDR MHz) (HTT * HT Driving Strength) = HT MHz (on the divisor ratio line, there’s a specific note to round up, this means when you have *any* decimal value, even if it’s below .5, please round it UP!) Memory Dividers shown as decimals for the above equation: (put the decimal in the (memory divider) spot in the second line above) 200MHz (400) = 1/1 (1 / 1 = 1) 183MHz (366) = 9/10 (9 / 10 = .9) 166MHz (333) = 5/6 (5 / 6 = .83333) 133MHz (266) = 2/3 (2 / 3 = .66666) 100MHz (200) = 1/2 (1 / 2 = .5) HT Driving Strength info (this is just relevant information for your AMD/ATi HT it's called "HyperTransport" & it's a function or 'bus' of the motherboard) - your HTT (that's attached to your CPU multiplier) multiplied by the HT Driving Strength Multiplier below = your motherboard's true HT MHz speed (they're interlocked 'busses') (i.e. 200MHz HTT multiplied (*) by 5 = 1000MHz HT) 1000MHz = 5X 800MHz = 4X 600MHz = 3X 400MHz = 2X OK, with all that fresh in your mind, we're going to use the math equation for an easy and quick lesson (less any voltage adjustments - that all comes later...we just want to show how the math works and get familiar with it. (9 * 300) = (2700)MHz (remember? - that was your CPU Multiplier times your HTT MHz) (9 / (.833333)) = 10.8 (round UP, so = 11) (remember? - that was your CPU Multiplier divided by your Memory Divider shown as a decimal, then rounded to the next higher whole number) (2700 / 11) = 245.45MHz (* 2 = 490.909MHz DDR) (remember? - that was your CPU Frequency from line 1 in the equation divided by the sum of line 2 in the equation) So, you can see your DDR400 RAM sticks are actually running at 491MHZ speed. (this isn't doable with the stock RAM timings) (300 HTT) * (4X HT) = (1200MHz HT) (this *may* need to be adjusted, but you'll get to all that later - you've got some serious work to do first!) So, here's the math again without all the verbiage (and so you can get used to the way it looks and works) : (9) * (300) = (2700) (9) / (.833333) = (10.8) (rounded = 11) (2700) / (11) = 245.45 (* 2 = 490.909) (300) * (4) = (1200) We're lucky. I have proven the A8R32-MVP Deluxe capable of 1500MHz HT - where most boards out there struggle to attain 1100MHz HT! But again, just because my A8R32-MVP Deluxe *will* run at 1500MHz HT doesn't mean that yours will...don't get that set in your head. And, another thing on HT: as long as you're close to the 1000MHz mark with the actual HT speed (after doing the math of multiplying HTT and the HT multi) - you're just fine...going over 1000MHz doesn't give you a performance INcrease per se, and decreasing it to below 800MHz doesn't give you a performance DEcrease at all...just best to use the math to stay near the 1000MHz mark. __________________ Under NDA Under NDA 4 X 2048MB (Under NDA) 5970 Engineering Sample 7 X WD 500GB 7200RPM 16MB Cache SATA2 HP DVD1040 X-Fi Fatal1ty Extreme Gamer w/ Creative Gigaworks S750 7.1 Surround OCZ GameXstream 1010W CoolerMaster COSMOS S *Modified*(Sorry guys, I can't talk about what's in my system, so don't ask) Last edited by Psychlone : Aug 7, 2008 at 09:53 PM.  