ATI 3850/3870 Voltmod thread

[PPInDaHouse]

I can also confirm that the voltmod works. 3870 VCore now at 1.42 after using a #2 pencil.

what image did you used for gpu pencil mod?

[VoRtAn_MaDgE]

what image did you used for gpu pencil mod?

This i guess

[PPInDaHouse]

no, that's for 3850 card, I want for 3870

btw I can run Nature at 1428mhz on rams without any mod, stockcooled

but core only 900

[Rumon]

no, that's for 3850 card, I want for 3870

btw I can run Nature at 1428mhz on rams without any mod, stockcooled

but core only 900

Clint, HousERaT and i can confirm that it also works for the 3870.

I managed to get it to 1.49v, Core@958.5 for gaming and 985 3Dmark06

had a hard time shading it though using a 3B pencil

[Rick Hunter]

Here's my pencil mod results on my HIS 3850 512 MB IceQ3 Turbo.

__ohm Volt MaxMHz Temp
2.26K 1.31V 826 MHz 48
1.38K 1.36V 850 MHz 51
1.45K 1.39V 876 MHz 53
1.13K 1.44V 904 MHz 56

Penciling in 1.13Kohm was not easy.

Scales pretty linearly across the board. Stable in 3DMark06 and AtiTool artifact tester.

I also slapped on a different fan onto the original heatsink, an 80 CFM Delta 80mm @ 70%. Brought down the temps by about 7 degrees on average.

[Rick Hunter]

Here's my pencil mod results on my HIS 3850 512 MB IceQ3 Turbo.

__ohm Volt MaxMHz Temp
2.26K 1.31V 826 MHz 48
1.38K 1.36V 850 MHz 51
1.45K 1.39V 876 MHz 53
1.13K 1.44V 904 MHz 56

Penciling in 1.13Kohm was not easy.

Scales pretty linearly across the board. Stable in 3DMark06 and AtiTool artifact tester.

I also slapped on a different fan onto the original heatsink, an 80 CFM Delta 80mm @ 70%. Brought down the temps by about 7 degrees on average.

Update:

After a day, the pencil mod wore off a little bit. I redid the pencil mod with the aforementioned technique (over the top of the resistor). Here are the new results:

__ohm Volt MaxMHz Temp
1.13K 1.44V 904 MHz 56
1.19K 1.43V 891 MHz 56
0.99K 1.46V 918 MHz 56
0.99K 1.46V 918 MHz 49 (delta @ 100%)

Ambient temp is about 23-24 degrees.

[Wallboy]

Update:

After a day, the pencil mod wore off a little bit. I redid the pencil mod with the aforementioned technique (over the top of the resistor). Here are the new results:

__ohm Volt MaxMHz Temp
1.13K 1.44V 904 MHz 56
1.19K 1.43V 891 MHz 56
0.99K 1.46V 918 MHz 56
0.99K 1.46V 918 MHz 49 (delta @ 100%)

Ambient temp is about 23-24 degrees.

Wore off? So when applying this mod, one has to redo it quite often or what?

[Clint]

Clint, HousERaT and i can confirm that it also works for the 3870.

I managed to get it to 1.49v, Core@958.5 for gaming and 985 3Dmark06

had a hard time shading it though using a 3B pencil

Excellent!

I'm down at 1.0kOhm...was a real hassle to get it that low, you must have gotten it down to 700-800Ohm or so..

Care to explain the method of shading, did you do circles around the resistor or some other technique?

[KainXS]

This i guess

is that really for the 3850, I tried shading that on my 3850 256MB and its not working, anybody got an idea