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- Dec 28, 2005
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P5WD2-E Board Mods
Before doing this mod, Vcore was drooping over 90 millivolts on high OC loads.
After mod, droop is 10-20 millivolts.
Modification is simple, Add a 50k variable resistor or potentiometer across pins 17 and 18 of Analog Devices ADP3181 DC-DC 3 Phase controller http://www.analog.com/en/prod/0,2877,ADP3181,00.html. There is also a 20k resistor in series with the pot to prevent damage if the pot is turned fully in the direction that causes zero ohms, causing a short across the pins which may damage the device. Total resistance range is 20-70k. You can also just use a 100 pot without the resistor, but make sure you don't turn it all the way down to zero ohms. (see Rev 1 for the 100k setup). A multi turn pot works the best, this one is 25 turns.
After soldering, adjust ohms reading for 40K between the pin 17 and 18, with power off. Run PRIME95s and check the droop, lower the resistance and keep running PRIMES until you get about .015v droop or keep lowering resistance until you are satisfied. I've gone as low as 20 ohms and any lower may cause the output voltage to oscillate. You can carefully make adjustments while running. Works like magic. Mine is set @ 25 ohms. Actual voltage winds up about 70mv higher than BIOS setting so make sure you set BIOS lower before powering up the first time.
****** MAKE LEADS NO LONGER THAN NECESSARY *****
Rev 2: 20k resistor in series with 50k pot.
Bulletproof solution, Can't damage anything regardless of pot setting
Rev 1:No resistor, 100k pot.
Works but be careful not to turn the pot down to zero ohms.
Actual Results. CPU=570@ 4.65GHz x14, 1325fsb
Alternate mod soldered to pads:
Vdimm mod:
PS: Do at your own risk... PM me if you have questions, be glad to help
EDIT: March 9th, 2006: If you solder to a resistor, rather than a open pad, be really careful not to overheat the resistor which could damage it. Not to worry with most radio shack pencil type irons, but some soldering guns and stations have enough heat to damage the component if you heat it up more that a few seconds.
Here's another twist: Proth's official GHETTO MOD. Sharpen a #2 or any other soft lead pencil really sharp. Jam the tip of the pencil between Pins 17 and 18 of the Buck Boost converter/regulator. Rotate the pencil while applying slight downward pressure, then snap off tip of lead so it remains jammed between the pins. Low risk, should keep droop under 20 millivolts:
EDIT: April 4 2006. Check out this pic from UBI who actually did this mod...He says it actually works great
Before doing this mod, Vcore was drooping over 90 millivolts on high OC loads.
After mod, droop is 10-20 millivolts.
Modification is simple, Add a 50k variable resistor or potentiometer across pins 17 and 18 of Analog Devices ADP3181 DC-DC 3 Phase controller http://www.analog.com/en/prod/0,2877,ADP3181,00.html. There is also a 20k resistor in series with the pot to prevent damage if the pot is turned fully in the direction that causes zero ohms, causing a short across the pins which may damage the device. Total resistance range is 20-70k. You can also just use a 100 pot without the resistor, but make sure you don't turn it all the way down to zero ohms. (see Rev 1 for the 100k setup). A multi turn pot works the best, this one is 25 turns.
After soldering, adjust ohms reading for 40K between the pin 17 and 18, with power off. Run PRIME95s and check the droop, lower the resistance and keep running PRIMES until you get about .015v droop or keep lowering resistance until you are satisfied. I've gone as low as 20 ohms and any lower may cause the output voltage to oscillate. You can carefully make adjustments while running. Works like magic. Mine is set @ 25 ohms. Actual voltage winds up about 70mv higher than BIOS setting so make sure you set BIOS lower before powering up the first time.
****** MAKE LEADS NO LONGER THAN NECESSARY *****
Rev 2: 20k resistor in series with 50k pot.
Bulletproof solution, Can't damage anything regardless of pot setting
Rev 1:No resistor, 100k pot.
Works but be careful not to turn the pot down to zero ohms.
Actual Results. CPU=570@ 4.65GHz x14, 1325fsb
Alternate mod soldered to pads:
Vdimm mod:
PS: Do at your own risk... PM me if you have questions, be glad to help
EDIT: March 9th, 2006: If you solder to a resistor, rather than a open pad, be really careful not to overheat the resistor which could damage it. Not to worry with most radio shack pencil type irons, but some soldering guns and stations have enough heat to damage the component if you heat it up more that a few seconds.
Here's another twist: Proth's official GHETTO MOD. Sharpen a #2 or any other soft lead pencil really sharp. Jam the tip of the pencil between Pins 17 and 18 of the Buck Boost converter/regulator. Rotate the pencil while applying slight downward pressure, then snap off tip of lead so it remains jammed between the pins. Low risk, should keep droop under 20 millivolts:
EDIT: April 4 2006. Check out this pic from UBI who actually did this mod...He says it actually works great
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