ATI 3850/3870 Voltmod thread

[crio]

try cooling them pal and see.Which mod did you say u used?Can you tel me the post #???

[GenTarkin]

try cooling them pal and see.Which mod did you say u used?Can you tel me the post #???

forums.techpowerup.com/showthread.php?t=48544

that one =) its in this topic also but not sure of the page number.

[crio]

I have tried the r1222 mod but can't get past 1.45V.I have hd3850 256 sapphire randeon.The resistance has dropped to 0.6.The temps are great cause of my w/c (65C max).
I also tried the second mod at C613 but can't get it to work.What exactly do i do?I need help in order toget past tha 900mhz at core.With 1.45 i max it there.Tried 920 but 3dmark06 froze.
IN Need of 1ghz at core.

[crio]

CAn anyone help me?

[ceemic]

I got another Gigabyte HD3870 512MB DDR3
http://ceemic.pri.ee/hardware/hd3870_2/hd3870_01.JPG
http://ceemic.pri.ee/hardware/hd3870_2/hd3870_02.JPG
http://ceemic.pri.ee/hardware/hd3870_2/hd3870_03.JPG

Time to renew my 3D2003 WR
Without Vmod, it did 972MHz in warm room

[NapalmV5]

sapphire 3870 512MB @ 1050/1360 test passed on stock cooler/air/vgpu mod one and only mod

[ceemic]

NapalmV5, what Vgpu? 3D stable?

[NapalmV5]

i havent monitored voltage yet.. just used fixed resistor

can bench higher but this is what im gaming @ 1ghz core/1.3ghz mem on the stock cooler/air

[NapalmV5]

i gained 15mhz from just 1 cap replaced



its not from the lower temp/mem

its promising.. ill recap some more..

[ceemic]

What has capasitor to do with voltage? You mean resistor?

[Jor3lBR]

sapphire 3870 512MB @ 1050/1360 test passed on stock cooler/air/vgpu mod one and only mod

Thats great NapalmV5!

But what CCC your using? Mine is blocked @ 885Mhz.

[NapalmV5]

What has capasitor to do with voltage? You mean resistor?

capacitor.. what capacitor has to do with voltage: filters.. expands or shrinks frequency..

Thats great NapalmV5!

But what CCC your using? Mine is blocked @ 885Mhz.

thanks

http://www.iax-tech.com/video/3800biosmod/03.htm

[ceemic]

NapalmV5, sorry, I misread Your text. Ofcourse caps can give us higher OC stability. For higher Vgpu You used fixed resistor
Do You have any pics from that mod? There are 4-6 caps in PWM, am I right? You parallel-soldered some electrolytic ones or You removed the original and replaced it with higher tantalum-cap?

[Jor3lBR]

capacitor.. what capacitor has to do with voltage: filters.. expands or shrinks frequency..



thanks

http://www.iax-tech.com/video/3800biosmod/03.htm

Thanks mate I'll see what I can do I just did a light mod (100k pot on DDR and bumped the core volt a bit).


BTW those are remarkable scores kinking some 4050 4070 butts!

[NapalmV5]

NapalmV5, sorry, I misread Your text. Ofcourse caps can give us higher OC stability. For higher Vgpu You used fixed resistor
Do You have any pics from that mod? There are 4-6 caps in PWM, am I right? You parallel-soldered some electrolytic ones or You removed the original and replaced it with higher tantalum-cap?

i didnt parallel cap/add caps.. ive tried it though.. @ diminishing results

so all i did to gain the 15mhz is i removed the 330uf cap (C730) and replaced it with a 1000uf blackgate fk cap

bam! easy 15mhz for a total of 1065mhz

Thanks mate I'll see what I can do I just did a light mod (100k pot on DDR and bumped the core volt a bit).


BTW those are remarkable scores kinking some 4050 4070 butts!

lol

the vddr mod offered only 10mhz so i removed it

[ceemic]

so all i did to gain the 15mhz is i removed the 330uf cap (C730) and replaced it with a 1000uf blackgate fk cap

bam! easy 15mhz for a total of 1065mhz

Hmm, I haven't the card atm my hand so I only have an older pic: http://ceemic.pri.ee/hardware/hd3870/hd3870_07.jpg
C730 is 16V/100uF

[NapalmV5]

330uf cap @ sapphire red pcb

ill post a pic later..

[Jor3lBR]

330uf cap @ sapphire red pcb

ill post a pic later..

NapalmV5:

Yes maybe create a little guide those info are precious and the fact that you're able to share them is even more!

I wish I could ad those caps with the cards in place because I already finished my system and it would be a little tough to take them out.

[panzerchaos47]

Just wondering is there different types of 100k ohm Potentiometer? I have one it's the Micro-Size Potentiometer from Radio Shack but they don't carry the rectangle shape ones.

[ceemic]

panzerchaos47, "size" doesn't mather asfar it's multi-turnable (15-22 turns usually).

[mop231]

question, i have powercolor radeon 3870, on ddr3. does anyone know bout some vmod on it or it doesnt matter ? all are on same pcb?

[ceemic]

mop231, is the IC also the same? http://ceemic.pri.ee/hardware/hd3870/hd3870_13.jpg (NX2420)

[mop231]

I'll post a pic of my card pcb ok?

[ceemic]

mop231, do that.

[NapalmV5]

sapphire 3870 @ stock cooler/air 1065/1350 passed

i gained 15mhz from just 1 cap replaced

his 3870 @ stock cooler/air 1090/1320 passed


not done yet.. will try 20k resistor and see if passes 1.1ghz core on air