posted
I'm starting a new thread for just the Vcore mod. We have now tried the Vdimm mod to increase the Vdimm to 3.3V and there was no change in overclocking ability. We have tried the Vdd mod to get Vdd to 2.0V and there was no change in the overclocking ability... Only 1 thing left.. I had tried this before and failed in getting the Vcore up at all, but another look won't hurt...
While this mod is for the N2PAP-Ultra, I believe the N2PA series probably use the same PC board hence the mod will probably work on any N2PA. Check the pictures to see if yours looks like mine....
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003
posted
OK, here is the circuit we're talking about. It's stragically placed along side the CPU in order to distribute the Vcore amperage with as little loss as possible. The Jetway uses a 2 phase, synchronous rectifier, step-down switching regulator for maximum efficiency. This circuit is standard throughtout motherboards today. Many use 3 phase versions of this.
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003
posted
EDIT: Pin 7 appears to be the correct pin, not pin 14...
The Shuttle AN35/N Vcore Mod is to go from RT9241A(our U10) pin #14 to GND, pin #13, with 50K variable resistor.
But our circuit is different. Try the resistor mod but DO NOT let the resistor go to below 10K ohms to start with.... Don't go below maybe 20K for the first try of the mod...
20K from pin #14 to Pin #13 ground should yield a 5% increase in Vcore. 10K should yield 10% increase.
Depending on exactly how the circuit was implemented, the resistor may not do anything....
Here's the pin numbers of the chip:
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003
posted
this would be nice for you guys having h2o system
but i wont be able to try this due to the fact that im using only a copper insert heatsink fan plus having a high ambient temperature in my place... setting my vcore at 1.7v already yields a 60c + temp bios reading...
posted
Reviewing the schematic above and the DS9241AB-02.pdf datasheet, it appears that pin 14 is not correct for the Vcore mod. Pin 7 is the inverting input of the internal error amplifier and it's that pin that controls the Vcore level. So the resistor to ground must be from pin 7...
Now, the darn chip is so close to the CPU, I can't hold a resistor on pin 7 to ground because the chip is under my water block...
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003
posted
Well, it took just under 2 hours between the time I gave up, to the time I posted with the Jetway at Vcore = 2.0V...
Now to some results.... Using my best set of parts, I can run Super PI now at 11X250... If the weather wasn't so humid I could get the CPU down into the teens for temp and I'm sure 11X255 or 11X260 would be obtainable.... The Jetway operates the exact same as the Shuttle, but has better OC options in the BIOS....
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003
posted
Those 38 seconds are very impressive, congratulations! You can have a good perspective of what you just achieved here: http://www.materiel.be/cpu/2004cpuv2/page9.phpPosts: 1843 | From: Rio de Janeiro | Registered: Jan 2004
posted
Thanks, my friend , And thanks for the link!..
For anyone wanting to try this, you need a very small tipped soldering iron, and a very strong magnifing device... I use a circular fluorescent lamp, that has a big magnifing lens mounted in it...
I ended up with two 22K resistors in parallel. It gives a measured 2.05Vcore... One 22K resistor gave 1.93Vcore which is too low...
I'm going to solder in a 10K resistor when I get back to the Office on Tuesday.....
CPU temp moved up somewhat, but nothing ridiculous...
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003
posted
Another piece of common sense advice, whenever you do a mod like this, or any of these mods, do not install components that are the best you have for the 1st power on. Install the parts that you can "afford" to lose.. The very first power on may be a problem if something went wrong with the mod...
-------------------- Too Many Computers,... Too Little Time ..... Com'on AM4! Posts: 26789 | From: Fire Island, NY | Registered: Feb 2003