How-to: Pencil mod your HD 3870!

[Random Murderer]

Ok guys, I'll include those two BIOS files in the next update, should be in a day or two when I get my trimpots in and actually hard-mod the card.

 

[trog100]

right then dudes.. proof.. not what i expected.. but the fanfix works.. how the hell i missed it cos its been sitting in my bios collection for weeks i dont know..

and for those that want to see proof the mod works here is my fur bench thingy.. check the card clock speeds.. a modest voltage increase fron 1.35 to 1.4.. nothing extreme..

downsides to the fanfix bios.. noise.. and the CCC limit drops back to 885.. but there are other methods of getting more then the CCC lets u have..

trog

ps.. odd the fanfix temps are a bit higher with the card going way slower and the fan going faster than a fixed 74% useing rivatine.. gonna look into this a bit more..

 

[trog100]

a little more.. the problem here is the core speed goes up in 13 mhz jumps.. it took 945 on the setting to get a true 931 on the core.. it might do a true 944 which would be the next jump.. dunno.. i am bit surprized it goes this far..

gonna put this one in the fur benchmark thread..

trog

 

[Reset]

See I told you Trog!

Trog I've been working on PC's since I owned my first Tandy 1000 EX, no hard drive but 2 5.25 floppies and a screaming 300 baud modem. Only internet was local or long distance BBS's. I've been building my own computers since then. I have 3 fairly fast water cooled computers in my computer room now. Two Vista's and one Fedora OS operated, oh and a XP Pro laptop too. Yes i'm a geek for sure! I get behind the times and screw up sometimes these days, i.e. calling the flash a volt mod. But normally I'm right!

Didn't want to be off topic, just letting everybody know who I am since I am new here.

I think they did the fan mod just right where you get good coooling without too loud a fan speed. Now it would be nice to be able to use the pencil mod and the fan bios mod with more frequency tweaking room. I saw RM said something about that I think.

 

[trog100]

i made a mistake.. been looking for a fan speed increase bios for ages.. i found that one ages ago how the hell i came to the conclusion it didnt work i have no idea.. i try every one i can find and use the rivatuner monitor to check them.. somehow that one slipped thru.. he he he

post it in the forum it will get lost in here else..

the problem is these bios's show up in various places but nobody knows where they come from or who did them.. i cant do them.. random cant do them.. i do have a tool that compares them.. i can see the differences with the fanfix bios compared to another but its all "hex" to me.. he he

your fanfix and my old fanfix are identical.. which was why i said it didnt work.. my mistake was made weeks ago..

whatever changes the fan speed isnt much.. i do know that.. its all right at the front end with the 071 bios's.. i thought it would need more alterations but it dsont need that much at all just few.. no more than changing the core and memory speed does..

i have been looking closely trying to spot the exact difference that alters the fans target temp but as yet aint sure exactly which changes do it..

there is no real gain from using the higher core and memory speed bios's.. the pencil mod works but is hit and miss.. lots of folks just get dust.. which falls off.. my slightly roughening the surface before applying the pencil seems to be permanent.. but getting the exact voltages u want isnt easy.. with the surface slightly roughened its all too easy to get way tooo much.. with the surface not roughened its the opposite.. rub like hell and get nowhere..

i am now running a very small voltage increase.. 1.34/5 to 1.39/4.. i would like a smidge more say 1.42.. but cant be arsed to keep trying to get it.. 1.5 would be good for suicide runs with special cooling.. i tried it with 1.5 and things got way too hot.. i should have run a fur bench up there just for bragging rights.. he he

trog

ps.. i am now game stability testing my card at the max CCC setting of 885 core which is a real 877.. .. all the silly high core speeds are just for benching..

 

[Random Murderer]

Ok, my trimpots arrived today, but I'm busy tonight, so I'll work on the card tomorrow. Expect pics, a hard-mod guide, and the BIOS section to be updated.

 

[Reset]

whatever changes the fan speed isnt much.. i do know that.. its all right at the front end with the 071 bios's.. i thought it would need more alterations but it dsont need that much at all just few.. no more than changing the core and memory speed does..

i have been looking closely trying to spot the exact difference that alters the fans target temp but as yet aint sure exactly which changes do it..

Well personally I would be OK with more noise from my fan to get some more cooling. I'll be happy for now I guess since this video card is brand new. Also I have never done a pencil mod and was wondering whether the pencil would fall off or not. I may hold off till RM see's how his variable resistor trimpots work out. I wouldn't mind soldering if it isn't too tight a job.

BTW, I notice some screen flicker recently with my OC at the settings I mentioned. I may need to turn it down a few notches.

 

[Rhinofart]

It's about time.

Well guys, my parts finally showd up yesterday so I spent the day putting it all together. Now stupid work is getting in the way of me trying the mod out on these puppies. But I did slap 3DMark on my system to try them all out at stock speeds before Moding, and OCing them. 3DMark 06 first run was 12505 in crossfire. 3DMark 05 was 18196 in crossfire. Bear in mind this is only on an X2 6400+ and everything is running stock speeds. I'll grab some screen shots the post them the next time I get some benchies done.

I'm very much looking forward to that mod guide RM!

 

[TonyStark]

Excellent guide Random Murderer.

I've been running this pencil mod for a few weeks after finding it on xtremesystems. Didn't bother measuring voltages (I'm crazy like that).

My card hits 70 at full load with the VF900 and AS5.

905/2700 3DMark06 stable (still testing)
877/2400 Crysis DX9 stable (still testing, 905 crashed after 2 hours play).

Before vMod 825/2400 crashed in Team Fortress. Bad card for OC'ing.

 

[Reset]

Since there are some 3dmark06 scores here I thought I'd add mine. I had to lower my timing down some, but I am getting a 3dmark06 score of 12,171 with the card settings @ 855/2662. I am surprised that the 3dmark06 Crossfire post above is only 12,505. That doesn't make me want to buy another HD 3870 for Crossfire!

 

[Ravenas]

I've got to thank you for this how-to because I'm about to buy this card, and then you and I need to have skype tech support session lol.

 

[kenkickr]

I should be getting my 3870 next Tues or Wed so I'll try this vMod out.

 

[Rhinofart]

Low scores?

Keep in mind that this card, cpu, and ram are all running stock speeds right now. I'm running windows xp pro x64 edition if that also helps clear some stuff up. I'm going to dual boot tomorrow and put Vista Ultimate 64 Bit or 32 Bit. Not sure which version yet. Any Ideas?

 

[trog100]

sounds like your system isnt running with crossfire enabled rhino.. not as i know what it is..

trog

 

[Reset]

Rhino, I hate to ask this because you probably did, but did you uninstall then reinstall your video drivers when you installed the second card?

I think the same thing still depends on your needed drivers whether you want to run Vista 32 or 64 bit. I don't think there is a real advantage to benchmarking your graphics in Crossfire. I could be wrong though!

Also about the 3dmark scores, I think I am runng a little faster system with my CPU@3.61ghz and ram@1066. That's probably the difference? Since I dual boot I might try my 3dmark score with XP Pro and see what I get there.

Edit: Score on XP Pro 3Dmark06 just slightly higher than with Vista Ultimate. Vista=12,171 XP=12,288

 

[Rhinofart]

Crossfire Noob here.

Well to be honest this is my first setup with more than 1 Video Card in it. I upgraded from my single ATI AIWx800 to this. It's a fresh load of windows, I put both cards in the motherboard at the same time (before installing windows) and then installed windows, installed all the updates, drivers, etc, and the last step (after Dotnetfix) I installed the latest Cats right from ATI/AMD. CCC says that crossfire is enabled, and when I disable it and run the 3DM05 there is a differance in score. Is there something I should do, or should have done to get better performance? When I do the results browser online it says of all the similar systems to mine, I am the fastest.

Reset, are you using just a single card?

 

[Source]

Ok, my trimpots arrived today, but I'm busy tonight, so I'll work on the card tomorrow. Expect pics, a hard-mod guide, and the BIOS section to be updated.

Please Please Please post your hard mod pics and how-to. I will do it as soon as you post it!

 

[largon]

HD3870 hardmod guides:
http://www.xtremesystems.org/forums/showpost.php?p=2574894&postcount=1

 

[Source]

HD3870 hardmod guides:
http://www.xtremesystems.org/forums/showpost.php?p=2574894&postcount=1

I seen this one, but since it's my first volt mod, I was hoping more for a step-by-step guide from RM.

 

[Random Murderer]

I seen this one, but since it's my first volt mod, I was hoping more for a step-by-step guide from RM.

Give me a few hours.
I've got all my materials ready, and I'll actually be performing the mod in a bit. After that, it will take me an hour or two to get the guide to my liking, so don't be expecting a full guide until later tonight.

 

[Source]

Give me a few hours.
I've got all my materials ready, and I'll actually be performing the mod in a bit. After that, it will take me an hour or two to get the guide to my liking, so don't be expecting a full guide until later tonight.

Awesome, good luck with it. I don't even have the materials yet. If you could also put those in your guide that would be GREAT.

 

[largon]

Source,
You need:
solder iron, 100kΩ variable resistor, 2 pieces of thin wire, multimeter

Here's what you need to do:
1. Solder one piece of wire on the middle leg, and the other piece on either of the outer legs.
2. Tune the resistance between the free ends of the wires to 100kΩ.
3. Solder the free end of either wire to a "mod solder point". (refer to the guide pics)
4. Solder the free end of the other wire to a ground. (doesn't matter what ground you use)
5. Done!

 

[Reset]

Yes Rhino, I am only using one card.

 

[Rhinofart]

Stock Volt Mod???

I was just taking the readings for reference on my card so I could do the pencil mod and found a very strange thing. My cards are both already running at between 1.4 and 1.5 volts on the VGPU testing ports. Has anyone else had this? I'm also running on the stock bios at 851 core, and 1200 RAM and everything is stable. Also people are saying my 3DMark 06 score looks like I only have 1 of my cards running (IE Crossfire disabled) Any way to easily confirm that as my 05 scores are fairly good, and I know that 06 is more of a CPU dependant thing.

 

[largon]

Rhinofart,
Are you sure you're not experiencing a faulty reading due to low battery (eg.) on your DMM?