How-to: Pencil mod your HD 3870!

[sneekypeet]

Oh Ok I just haddent seen one stock....I was feeling cheated...lol

 

[Random Murderer]

Apparently the second pencilmod point works better.

I tried both, and I prefer the one on the resistor, but like I said, that's just preference.
Both work, both do the same thing.

 

[Random Murderer]

New breakthrough. It seems that for every 7.808Ω the VCore is increased .001V.

Anyone care to confirm?

 

[KainXS]

how about a 3850 guide random

 

[Random Murderer]

how about a 3850 guide random

If someone wants to donate a 3850 or lend me theirs, sure, lol.

 

[Cold Storm]

Thanks man, love the mod! still can't believe it only took less then 20 mins to get at 1.030! See you later with the dogs...

 

[Random Murderer]

UPDATE!
Added BIOS mods.

 

[Random Murderer]

You'll all be happy to know I'm working on a VMem mod.
This one will be a bit tougher, as all the info I have is the measure point.

EDIT:
I have good news and I have bad news.
Good news: I found the VMem mod points, and also managed to get a resistance reading- it's 4.17KΩ on my card.
Bad news: The points are legs of an IC, so no pencil mod here. It WILL require soldering, something I don't think I'll risk on a $250 card.

 

[Ati Addictive]

Sorry little noob under this subject but what is pencil modding? something like Volt modding?

 

[Random Murderer]

Sorry little noob under this subject but what is pencil modding? something like Volt modding?

It is a voltmod that requires no soldering, just a pencil.

 

[trog100]

my pencil mod experience.. this is the second mod.. the yellow mark one not the one random used..

sharp old HB 2 pencil.. i tried a few different pencils by drawing a small line and testing the resistance.. the old one worked best..

its all very small and fiddly.. the first attempt produced no voltage increase at all.. my stock was at 1.34.. the second attempt took it up to 1.6.. we decided (rapidly he he) this was too high and removed it..

the next ten or so attempts produced no results.. we decided the 1.6 volts was a fluke caused by loose dust.. the problem being the pencil would not adhere to the shiny PC board surface..

next try.. a very small watch makers screwdriver.. roughened the surface up slightly between the two pins.. applied some lead and put the card in the machine.. it wouldnt boot.. showing no voltage to the card..

panic.. then cleaned it all off.. things back okay end of panic.. next go.. still wouldnt boot.. brushed it off with small brush.. it booted and went straight over to 2.5. volts.. another panic hit of the off button..

sooo.. the very slight roughening of the surface makes a major difference.. the pencil lead adheres.. danger time..

sooo a couple of light pencil strokes as opposed to heavy rubbing and back in the machine.. a nice 1.5 volts..

boots into windows and gives it a fur bench run.. at 1.5 volts the card runs over 100 C and the lazy stock fans goes up to a noisy 78% trying to keep the card at the target temp.. the temps levels off at 102 C..

the whole thing is too noisy for me so we remove the lead and try again..

we end up with 1.4 volts.. the stock cooler runs its fan a little quicker (50%) but keeps the card at the same 92 C as it does at the normal core voltage..

1.4 volts seems a nice compromise.. i ran a 2006 run at 895 core and it made the trip.. i havnt really tested properly (gaming stable) yet it takes time.. but there is a definite improvement in possible core speeds..

i also havnt crashed the card yet so it might go higher it might not..

i am not into extreme suicide clocking attempts.. just a nice gaming stable without excessive noise.. improvement.. i seem to have got that..

trog

ps.. your top fur bench 3870 score is in danger random.. i just saw 3400 while running some quick tests.. he he he

 

[nflesher87]

trog you give such entertaining recounts...I was literally lol'ing

 

[Reset]

RM I have this HD 3870 fan mod that works great on my HD 3870. I think this would be good if you or somebody else could merge this mod and your volt modded bios flash together. Just with this fan mod I was able to get much better OC than without it. Right now I am running with stock fan @ 872/1376

This fan mod keeps the temps closer to the 60-70's. Here's the mod I used:

 

[trog100]

there is no 3870 volt modded bios.. i am interested in the fan mod bios thow what does it do exactly.. what is its history.. sorry for being a bit dubious.. but having searched high and low for a bios that targets 75 C instead of 90 C and not found one.. i am a bit doubtful..

trog

ps.. no need for a history.. its one i have tried long ago.. it does unlock the 864 blackscreen limit but does nothing at all as regards fan speed.. shame.. its the same as the one random is using but has lower clock speed at default.. just a normal version 071 64k bios.. it was one of the first ones that appeared when folks were discovering the fix for the early 067 blackscreen bios..

its also worth nothing that the faster default core speed bios either the 830 one or the other faster ones do extend the clocking option in the CCC from 885-ish to 1500-ish.. but they do not make your card go any better than the stock 071 777 core speed bios.. only your skill with the mod will do that..

i think randon should unclude this 830/1200 bios i have attached into his bios download.. its safer.. up to him thow..

 

[Reset]

Sorry I should have said frequency mod or something else, that's right it's not a volt mod. The fan speed mod I sent worked for me, here is where I found out about it.

http://forums.amd.com/game/messagev...d=90359&STARTPAGE=2&FTVAR_FORUMVIEWTMP=Linear

This is the link where I found the mod.

http://www.rage3d.com/board/showthread.php?t=33912408

 

[trog100]

i have been testing these things for nearly the past six weeks since the cards first came out.. ati have set the normal bios to target around 90 C.. ati have chosen this temps as a working temp.. nothing wimpy about it.. its just running a little cooler is good for a small extra core speed increase not a great deal thow..

basically the card goes up to near 90 C before the fan speeds up.. at 90 C it runs at 40% which keeps the card at 90 C under heavy load.. take the card up to over 100 C (over volting) and the fan goes mad.. 78 % and it makes loads of noise..

in short at 102 C which quite clearly ati have set as the upper limit.. the fan does the business.. it does sound like a leaf blower thow..

i came across the bios u have under a different name a while back.. i think its actually an ati beta bios it has the words test bin in it.. but ts just a normal version 071 bios.. the same as comes on all but the very early 3870 cards..

i dont doubt where u found it.. its done the rounds.. but it runs the cards fan at exactly the same target temp as any other normal 3870 bios.. i did a thread on all this about 5 weeks back..

there are two cards out there that might differ from the norm fan speed wise.. the gecube turbo.. and the HIS turbo.. i have the gecube bios but dare not flash it cos it comes up with a sub systems dont match error message.. i havnt been able to acquire the HIS turbo one as yet..

these two cards use their own cooler not the stock ati one..

trog

ps.. just to make 100% sure i havnt run the wrong bios.. can u run the rivatuner monitor.. then run the fur bench to heat the card up and look at the monitor temps.. its the only accurate way of measuring these things.. thanks

 

[reverze]

i think randon should unclude this 830/1200 bios i have attached into his bios download.. its safer.. up to him thow..

Is this RM's BIOS with the tweaked memory timings with those clocks you mean?

 

[Deleted member 24505]

heres the 3850 vmod-

 

[Reset]

OK I hear ya. It worked for my Sapphire Hd 3870 though, because I can clock higher and see the difference in Rivatuner fan speeds, also better GPU temps. I uninstalled Rivatuner now since I just use the overclocking in CCC and don't seem to need the fan adjustments anymore.

Another thing that was improved was the fact that I could now run the ATI Overdrive Auto-Tune without the computer locking up.

Crysis was also showing artifacts and other strange annomilies before I used Rivatuner for the fans settings. Now it works overclocked and no need for Rivatuner. I may still want to try the pencil mod later so it would be nice to have a frequency mod that included the fan improvements.

 

[Deleted member 24505]

I found this too-

http://forum.purepc.pl/index.php?showtopic=245161

Theres links to lots of modded bios for all manufacturers.

 

[reverze]

The links not working for me.. just keeps trying to load

 

[trog100]

Is this RM's BIOS with the tweaked memory timings with those clocks you mean?

exactly the same just with a lower default core clock.. its a popular one used my many folks.. bit of laff really.. i spent ages tracing thru threads on extreme forums to find the best 3870 bios there was that people were talking about .. someone pointed at a thread and said it was a link to it there..

when i found it i had to smile.. it was linked back here to one posted by some guy called trog100... the 830/1200 one..

trog

 

[trog100]

well revers your insistence that it works is just gonna force me to reflash the thing and make sure.. he he

i will come back with some rivatuner pics to prove whether it does or it dosnt..

"it works for me" aint exactly good proof of anything to the rest of the world is it

trog

 

[Deleted member 24505]

The link works for me.

 

[EastCoasthandle]

I have been following this thread but haven't seen any results from the mod. Is that in another thread or something?