HD3870 Bios Modding (Hex Editor - Clocks - Voltages)

Hi,

after someone wrote to me who sold his 2900Pro and bought a HD3870 he asked me if i could mod his bios... so i took a closer look and with the knowledge from the 2900 modding the relevant offsets were found after a few minutes...

To understand the Basics of this modding please refer to the 2900 1st Post please... after you understood there how to proceed this should help ypu edit your own Bios...

Open your Bios in a Hex-Editor und search for the memory clock because its the same in all Power States (Mem clock as hex value is d8 b7 01)

after some searching i found this block:

http://s3.directupload.net/images/071203/zk3gi7c2.jpg

and after some conversions i finally could figured this out

http://s5.directupload.net/images/071203/t9u6rgrg.jpg

On one 3870 we could confirm that it worked, Here is the Bios File:

2D: 250/1126 with 1,0v (1,241v is default)
3D: 850/1250 with 1,327v (1,327 is the default voltage)

http://rapidshare.com/files/73980710/test.rom.html

What we could see, that his Overdrive didnt work afterwards, dunno why...

In this Bios i did not correct the checksum - it worked though... but perhaps it is like with the HD2900 cards, that some need a corrected checksum. We will see.

I had a feeling they would use a similar format :up:

I hope people that actually have the cards will help refine this.

I'm not sure you have it labeled exactly right, the 3870 uses 3dmode in windowed apps (unlike 2900) and may have a designated setting. It may be the third set of 3dclocks at the top of what you have labeled for thermals.

I really have no idea since I'm not playing with one, but that is my suggestion.

Quote:

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Originally Posted by super dank

I had a feeling they would use a similar format :up:

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These were my first thoughts, when i saw the values... I do not have a 3870 and I can´t play around with the values. It is just as you said ;)

Quote:

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Originally Posted by super dank

I hope people that actually have the cards will help refine this.

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If you can modify this 3850 bios with higher volts from IAX Tech then I can try it. I checked a hex editor on it and its the same concept

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

If someone can get a working 3870 bios with 1.4v and 1.5v in 3D mode I'll be willing to try them out.

I have tried this mod today and 900/1340 work ok for me :up: (even 930/1340 but I go for CF and only one of my cards can do this stock) but seems you cannot raise voltage with any values of the screen only decrease :shrug:

EDIT: I can raise the 2d state voltage but 1,4v/1,45v = 1,33v multimeter (seems it's the limit)

Bye
p€p|n0r@ng

Bios Vmodding doesnt work on these cards :( Only hardmods.
Does 900/1340 work on both cards?

Quote:

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Originally Posted by MorGo7h

Bios Vmodding doesnt work on these cards :( Only hardmods.
Does 900/1340 work on both cards?

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Yeah 900/1340 work 100% stable on both cards with stock cooler, I even tested 930/1340 on one card with success but the other card can't do this with stock vgpu...

Bye
p€p|n0r@ng

*HD3850 256mb all voltages to 1.327V (HD3870 3D level)
*Extremely experimental (need PCI card or blind flash if something goes wrong)
*checksum not fixed (most certainly not a problem)

Test at your own risk:
http://rapidshare.de/files/38011915/..._vmod.bin.html

EDIT: Clock lock at 862mhz core

Quote:

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Originally Posted by alexio

*HD3850 256mb all voltages to 1.327V (HD3870 3D level)
*Extremely experimental (need PCI card or blind flash if something goes wrong)
*checksum not fixed (most certainly not a problem)

Test at your own risk:
http://rapidshare.de/files/38011915/..._vmod.bin.html

EDIT: Clock lock at 862mhz core

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I checked this bios on Sapphire 3850 256MB and I have 1,24V in 2D and 1,28V in 3D

I think i read somewhere that BIOS V-Mods don't work, did you test that BIOS?

Maybe the bios vmod will work if you change the device id to "HD3870" from "HD3850". I will update shortly after I have made this mod. After all the driver is responsable for assigning the vcore so it's worth a try atleast :)

It's just weird that the driver doesn't read the correct values from the bios.

BIOS vmodding didn't work on the 3870. It was one of the first things we tried in the unleashed thread about 3 weeks ago. I've tried modifying the voltage tables up to 1.5v, and it does not budge. The checksum changes as soon as you modify anything on the original bios, and an incorrect checksum will give you a blank device ID / info when you try flash. The -f flag forces it, but you still dont get any change in voltage. guess has a tool to modify powerplay tables / clockspeeds, but he is under NDA and that tool is likely not going to be public.

So, pretty much if you want working vmods you either do hardware mod, or wait for w1z to get working software control in the next version of ATITool. You could probably try figuring out how to get a matching checksum and see if that makes bios modding work. But rather that wasting so much time to do that, imo you could just hardmod it and be done with it...

*edit*

Here's a thread talking about BIOS Checksums, in German though, the English translation below is very bad, didn't understand it well, so if anyone can take a look and tell us what he concludes?

http://www.area3d.de/forum/showthread.php?t=2545

http://translate.google.com/translat...hl=en&ie=UTF-8

Thanks.

Well it says that testing for the HD 3870 Bios can't be done because they don't have a card, they're looking for testers.
I have two 3870's, one form Gigabyte & one from HIS running CF. I just think it's worth to wait a little until threre's a new driver version, 'cuase the latest one is as young as the card itself. Greetings from Switzerland

anyone tested this bios yet???

Quote:

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Originally Posted by ChromeGunner

anyone tested this bios yet???

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yup interested to know that as well :)

Quote:

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Originally Posted by alexio

http://rapidshare.de/files/38027384/test2.rom.html

Checksum corrected, think it's ok now. Device id = HD3870 NEED TESTERS

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How did you take the correct checksum?

Quote:

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Originally Posted by alexio

http://rapidshare.de/files/38027384/test2.rom.html

Checksum corrected, think it's ok now. Device id = HD3870 NEED TESTERS

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Ill test it this weekend :)

Quote:

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Originally Posted by alexio

*HD3850 256mb all voltages to 1.327V (HD3870 3D level)
*Extremely experimental (need PCI card or blind flash if something goes wrong)
*checksum not fixed (most certainly not a problem)

Test at your own risk:
http://rapidshare.de/files/38011915/..._vmod.bin.html

EDIT: Clock lock at 862mhz core

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I tested this BIOS, it worked, i could go from 760 to 795, but why can't it go higher?


EDIT: Also, is it normal for the thermal sensor to read 45 idle and 60 load? without any modifications to the card!

Do not use this bios, i flashed my card to it and when i did the reboot Catalyst control would not work at all and Windows found a new pci device, so i installed Catalyst control again but windows kep on saying "Found new hardwar Pci Device" everytime i booted the pc, plus there was no diference on how high i could overclock, so i went back to my old bios.

Gunner:down:

Quote:

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Originally Posted by ChromeGunner

Do not use this bios, i flashed my card to it and when i did the reboot Catalyst control would not work at all and Windows found a new pci device, so i installed Catalyst control again but windows kep on saying "Found new hardwar Pci Device" everytime i booted the pc, plus there was no diference on how high i could overclock, so i went back to my old bios.

Gunner:down:

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Might have to do with the device ID being unreadable without the checksum fix. This should be fixed with the new bios I made.

Thanks for testing anyway ;)

""http://rapidshare.de/files/38027384/test2.rom.html

Checksum corrected, think it's ok now. Device id = HD3870 NEED TESTERS""""

that is the one i used and you said the checksum was fixed....just a heads up:)

Quote:

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Originally Posted by ChromeGunner

""http://rapidshare.de/files/38027384/test2.rom.html

Checksum corrected, think it's ok now. Device id = HD3870 NEED TESTERS""""

that is the one i used and you said the checksum was fixed....just a heads up:)

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Did you flash without the -f flag? If not then can you test if it works without the -f flag? If it works I'm sure that at least the checksum is correct now ;)

Sorry i don't get what your saying???:shocked:

in the dos command -f tells the program to force the flash, if it will accept it without the -f it should indicate the checksum is correct.

Quote:

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Originally Posted by jimmyz

in the dos command -f tells the program to force the flash, if it will accept it without the -f it should indicate the checksum is correct.

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Yes, that's correct :)

yeah i used winflash to flash the card, but i didnt have to force it it worked....

Quote:

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Originally Posted by ChromeGunner

""http://rapidshare.de/files/38027384/test2.rom.html

Checksum corrected, think it's ok now. Device id = HD3870 NEED TESTERS""""

that is the one i used and you said the checksum was fixed....just a heads up:)

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Tried this one on my sapphire 3850 256mb , i had to use the -f command as it said the part number did not match , after flashing no screen output :shrug:
flashed back to stock fine.

alexio, are you able to make a volt-modded bios for the 3870 card?
I'd like to overvolt my gpu up to 1.5V, but without hardware modding...

Thank you.

Bye

i think thats what we all want.... i'd be soooo happy if i could read the bios file accuratly and comprehensively understand how to get the voltages above what has been found to be the maximum. 1.5v has to come in a bios and it has to come from this forum... afterall this is XS.... now come on, one of you understands the file completely... experiment for the community and make a name for yourself...
to everyone that tries and fails... thanks for trying.....

I have tried to do a flash on my 3870, but it failed and I had to boot from a pci card, the reason that happened was probably because when I ran atiflash.exe without -f it says that it is "invalid PC image", but I check the size of the file it is exactly the same as the original so the bytes should not have changed, and the bios that I was editing works fine, maybe I changed too many parameters, I changed all of them, all clocks all the voltages of all the modes, maybe increasing the voltage to 1.5 was what killed it

is there any working solution for the 3870 bios volt mod problem jet? maybe someone with a gecube 3870 turbo III post his bios... from what i have read, the gecube card overclocks extremely well! maybe it has a higher vcore setting in the bios by default?

sorry to revive an old thread, but i can't find help anywhere else. my buddy has a new visiontek 3870 with the attached bios, and his vcore is 1.4. he wants to know if it's the bios causing higher stock voltage or something hardware. i had a crack at his bios in a hex editor, but it's not laid out like mine, i think it has extra lines in it.:shrug: can someone have a look at it and tell me what the voltages are in his bios?

Random murderer i have testet that bios and it is stock voltage 1.336volt on bootup and 1.341volt in 3d mode so his card must have some higher settings or the meassuring tool is off in its reading

Quote:

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Originally Posted by Riska

Random murderer i have testet that bios and it is stock voltage 1.336volt on bootup and 1.341volt in 3d mode so his card must have some higher settings or the meassuring tool is off in its reading

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thank you. i will let him know.

Ok your welcome

Quote:

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Originally Posted by Riska

Random murderer i have testet that bios and it is stock voltage 1.336volt on bootup and 1.341volt in 3d mode so his card must have some higher settings or the meassuring tool is off in its reading

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I've got a HIS 3870, if I flash to this BIOS I'll have 1.341v and not 1.327v?

Does the BIOS have have the fanfix, or 860MHz limit fix?

Thanks

Quote:

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Originally Posted by RealyPssd

I've got a HIS 3870, if I flash to this BIOS I'll have 1.341v and not 1.327v?

Does the BIOS have have the fanfix, or 860MHz limit fix?

Thanks

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none of that, it's just the stock bios.

Quote:

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Originally Posted by purecain

i think thats what we all want.... i'd be soooo happy if i could read the bios file accuratly and comprehensively understand how to get the voltages above what has been found to be the maximum. 1.5v has to come in a bios and it has to come from this forum... afterall this is XS.... now come on, one of you understands the file completely... experiment for the community and make a name for yourself...
to everyone that tries and fails... thanks for trying.....

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ATI stores clocks in a certain value (something that when it comes down to megahertz, it allows decimal clocks).

To search this particular BIOS for the clocks, switch the byte order.

http://s5.directupload.net/images/071203/t9u6rgrg.jpg

84 2F 01 is what is stored for the clock.
Put 01 2F 84 into Windows Calculator in scientific mode and you'll get 77700 decimal, and the core clock is, 777 Mhz.

84 2F 01
01 2F 84

Memory is stored as D8 B7 01. Reverse the byte order (D8 is a byte, B7 is a byte, 01 is a byte, which is 16 bits.) to 01 B7 D8 in Windows Calculator, and your memory is 112600, or 1126 MHz.

Voltage: 1327
1241

IS this possibel on the 3870X2

Hey !

Can u try to mod my bios ? Don´t want that 862mhz lock and i want a stock clock around 850/1000 if it´s possible.

" Note this is the DDR3 version of HD3870 "

http://rapidshare.com/files/101674110/3870.BIN.html