Dothan overclocking thread

[Spajky]

´ALO ´ALO,
Listen to me carefully, because I am gonna tell You only once! ...


@ ALL : Some additional ideas for better final OC : "MODding the Asus CT-479 ADAPTER!" further ... [final part]


[datasheet for Dothan & P4 required too]


If you watch your CT-479 from top view having power connector on your left /according to best pics I have not having the adapter myself/ :

- 3 chips on the right are IMO bidirectional cmos digital/analogic voltage clamp Bus switch ICs [Purpose: translating both way i/o Cpu signals to chipset & viceversa by adapting voltage levels; on P_M native boards not needed! Inividual quality of them determines adapters posibility of highest OCs; as an example: generic modded slotkets for Tualies OC-ed them better than PowerLeap slotket having this kind of ICs on-board]

- on left upper corner: IMO all-in-one switching (PWM) regulator/doubler IC [purpose: generating all other supply voltages needed for circuitry on board not using +5 or +12V, negative ones for example etc.] Certain SMD elements around it /caps & resistors/ determine its output voltages.

- big linear voltage regulator on the top of socket (probably using power feed_in +12V line, not sure) [IMO it procures 1,05 VccP voltage for the CPU i/o stages = 2nd core voltage - 1st time after 8y & P233mmx again true CPU differential/double powering!!!] Max current rating 2,5A !

- smaller linear voltage regulator (transistor?) taking previous source (VccP) to generate 0,63V i/o digital signals recognition state reference voltage (GTLREF). It is situated IMO in the left middle between power connector & that PWM chip.

- maybe there around is some other SMD transistor or lin.regulator (can´t find or see it-maybe in the middle between previous mentioned smaller voltage regulator & left upper socket corner!) to procure VccA voltages 1,5 or 1,8V for CPUs internal analog PLL clock generator (4 pins on CPU, see datasheet), but maybe is not even there & previous PWM chip takes care also for that!

- "missing" LowESR cap close upper to power connnector! Designed but not soldered maybe because of space problem with default cooler mounting? IMO serves filtering entering power line.

Linear voltage regulators (=LVR) have usually right pin Input, left pin Pilot-V & middle one (connected to its under metal base) is Output-lower/regulated_voltage. Mounted classic SMD transistor usually has terminals: single upper one Collector, right down one Emitter & Base /control/ pin on left. Both types can be positive (I+O or C-npn_Q terminals) on more positive potential) or negative (viceversa) as regulators mainly or even combined /positive regulator and pnp transistor instead & viceversa/.

Positive type "LVR" output voltage is determined/piloted usually by a middle point of a 2-SMD_resistors voltage divider going from its positive O terminal to Gnd (ground, mass, zero volt, black power conn.wire) & usually its minimal voltage is around 0,65V if its P terminal is directly [w/o resistor] tied to the Gnd (no need than for the other resistor!) if the LVR has fixed out voltage.

So to change its output voltage you just need to change those resistors value ratio, maybe by replacing them with other values or changing/diminishing/lowering their value by adding paralell to one of them much (10x?) bigger value resistor to lower a bit their value. If you add additional resistor to one going to Gnd, you will lower that output voltage; if you do that to the other one going to + , you will rise (overvolting!) output voltage. Easy !

For maybe changing that PWM chip voltages (I can´t decipher markings on it), you are on your own by finding apropriate datasheet for it for further procedures if needed!


Before you try anything (sure like always on your own risk not to blame anyone if sh1t happens): do modding stuff on the "Lab Table-non conducting surface" with only adapter involved /no Cpu, no MoBo!/; when measuring voltages & results of mods you will have to power it up by inserting the power connector powered from some PSU on. Should not happen anything, myself I powered many times MoBo´s On w/o CPU or anything inserted in & had no problems later.

Hope I do not have to mention, you have to have some practice with soldering tiny & delicate stuff & have proper soldering equipment with magnifying glass & light, calm hands & digital multimeter (DVM) too. If not (or not having guts), let someone else capable & equiped do it 4 U instead. But if you guys do mods on MoBo, this should not be a problem ... But first carefully find & measure default voltages on CT-479 /VccP, VccA & GTLREF ones/ !!! And for checking & doing mods is nice to have a spare adapter (cheap), MoBo (not so cheap) & some older Celeron_M (much cheaper than P_M!) if something goes wrong.


What is to accomplish? Overvolting over defaults certain voltages just like Vcore on MoBo! for same purposes!

- VccP = Cpu signal i/o stages powering them higher to 1,15V (max.1,2V!-same as "Vcc,BOOT"-default Vcore boot voltage); same effect like upping Vcore, but it has NEVER to be higher than VCcc,BOOT one to prevent reverse currents from Vcore inside the Cpu; files data corruption may occur! [I experieced this with my Tuallie time ago!]

- GTLREF = signal reference point /threshold between signal binary states/ setting it higher to 0,7V; helps chipset having higher margins between 0&1 digital states - better Fsb OC at higher FSB.

Those two task accomplished, Cpu & chipset will be consuming a tiny bit more current & heat a bit more, but only few % ! Shouldn´t be a problem! Max rating: GTLREF 2/3 VccP; max VccP same as Vcore = 1,6V but only if that low 1,2Vcore Vcc,BOOT problem is resolved before somehow, but even with that fixed, I woudn´t go higher for safe than 1,5 V VccP & 1V for GTLREF maybe with additional cooling of those 2 voltage regulators, not to overheat & kill them or damage the MoBo´s chipset or CPU !!!

- 3rd check: VccA voltage for internal Cpu PLL generator: for P4 & P_M is/should be 1,8V, while for Celeron_M can be also 1,5V (or 1,8V) max 1,57 (or 1,89V). Maybe this is selectable somehow by that CT-479 Asus adapter when C_M is inserted (maybe even Bios way) & that could be one of the reasons (lower V option!), why people using it could not OC for example that CM_350J more than max.170-180Fsb/2,3GHz regardless Vcore & cooling !!! (could be that SMD transistor/if there in the middle between mentioned smaller GTLREF voltage regulator & left upper socket corner is responable for this or even that PWM chip, who knows; a need 4 voltage measuring to know that!). Max current rating to Cpu there = 120mA !

- next possible enhancement to the adapter: adding some min.1000µF/16V "missing" LowESR cap there; since can not be mounted normaly because of HSF, would have longer connecting wires (not best), to fix that is a need to add on its contacts under the slotket an additional 100nF block-decoupling capacitor to further "clean" incoming power to the adapter (power stability)!


The effect of this "enhancements" (not counting some more heat generated) is that currents running thru Cpu & adapter/chipset are a bit higher thus lowering signal impedances & so less succeptible to disturbances (signal "ringing") following to beter stability of setup alowing higher OC. But is never good to exagerate with limit values (long term success & running it for years like my Tuallie) !!!

So ... "dr.Spajky" has finished his homework for You all & left the building, now its your turn to proceed ...

"...We will Clock it to the Moon, We will OC-it to the Moon to the end of this year, not because is easy, but because is Hard! ... J.OC.K !

My goal for Christmass: Celeron-M_350J 100% OC on Air, to replace my current Tuallie ...

Space (1,3@2,6GHz), the Final Frontier ...

Please snip a bit quoting! when replying ...