Vmod 3850 through BIOS apparently IS possible....

[GenTarkin]

I was following a post in a forum and was in different language...couldnt read it UGH and I dont have the forum I was on...
but one guy made a BIOS for the 3850 256MB that is labeled 7701000.zip and another 7701000a.zip

the first one did not work for me as it must have not had the correct checksum cuz the vendorID and bios name and all that information was blank when I flashed it. HOWEVER I tried the 7701000a.zip one and it raises the voltage tables up from the standard 3850 to 1.33v which isnt that close to the 3870?

Anyways, I did not take any readings with voltmeter BUT...before this bios I was only stable at 730mhz on the core and anything higher would freeze in games within minutes.
With this bios Im able to run games all day @ 770 even crysis....
I know its not hitting the 860mhz limit and I think a vmod via hardware is still a surefire way cuz I should get higher clocks...BUT I do think there is something to the software vmod also being that I gained 40mhz...

Bios was unfortunately .67 version which is the locked one but....that aside...
I think this might go somewhere....anyways leave feedback or tips or comments or whatever lol I would like to see if more can come from this.

PS I also confirmed the correctly changed voltage tables via rivatuners information readout of the powerplay modes...and indeed its been changed from its default to 1.33v =)

[chrisf.uk]

many thanks for this info , i went off to find the file and it definitely works on my sapphire 256mb card

http://www.benchmark.co.yu/forum/sho...=150149&page=3

Just testing and im up from 750 , to 789 , still testing but wont go higher without artifacts , core temp has gone from 42c load to 45c load , thats with a maze 4.

many thanks

[GenTarkin]

awesome....now we need someone who can adjust the voltages and do the appropriate checksums in english...LOL so we can read and follow it easier...also then we can test it out and see how effective the vmod bios is after all...since now its worked for 2 of us.

[chp]

Can you post these moded bioses?

[STEvil]

Maybe only certain voltage settings work? Interesting.

[metro.cl]

should these cards have software support for changing the volts? like HD 2900 on Ati Tools?

Then you dont even need a BIOS mod if so, just software to support it.

[chrisf.uk]

Can you post these moded bioses?

This is the one i used
http://www.benchmark.co.yu/forum/att...6&d=1197582504

[chp]

Thanks.

I'll try it ASAP. Stay tunned.

[os008]

Guys, i tried that 4 days ago, it works up till the 1.33v limit, i changed it to 1.4v but it didn't overclock even 1MHz more, don't think it works over the 3870 voltage.

Might be wrong, needs some testing.

[STEvil]

Topic here is 3850, not 3870's os008.

[GenTarkin]

Topic here is 3850, not 3870's os008.

I think what he was saying, that being a 3850 or a 3870...there is a hard limit on voltage past 1.33v...is the theory anyways.
It pertains both to 3850's and 3870's =)

anyways, through more knowledgeable voltage / clock settings in bios along w/ the correct checksum for those bios modifications...I believe would be a good analysis on whether it works or not...
I dont have the knowhow of doing it...rofl...I just stumbled across that page.
Ive been playing around a little more with my card and so far Ive taken it to 790mhz w/ the bios I posted earlier.

[chp]

This is the one i used
http://www.benchmark.co.yu/forum/att...6&d=1197582504

It doesn't work. Got many artefacts.

[STEvil]

GenTarkin - makes more sense. Thanks.

[os008]

Here's Stilt's BIOS, 862 limit fixed, 1.327v (3870's voltage), and already clocked at 760 core ...

760830-1327v-v071


EDIT: by the way, this BIOS isn't 100% as he gave it to us, i changed it to give more voltage and have more Core speed!

[chp]

Argh...
Seems none of the moded bios I try works. Thay causes troubles to my Connect3D HD3850-512 (blank screen or big artefats or unrecognised under Windows). Strange enouth since the card itself seems to be based on the standard ATI layout.

I post my own bios, someone can manage to modify It? I don't have enouth knowledge to modify it by myself. It will be greatly apreciated.

[os008]

Here's your BIOS modified.

By the way, the BIOS i posted above is for the 256MB version, sorry about not mentioning so before!

[chp]

Here's your BIOS modified.

By the way, the BIOS i posted above is for the 256MB version, sorry about not mentioning so before!

Many many thanks.

If I understand, one is default clocks but with 1.33v mod and the other is for 760Mhz core and 1.33v. I'm right?

I'll try it ASAP tonight..... Big Hope it work (crossed fingers)

[os008]

Hehe, i'm not responsible for any fireworks in the unforseen future :P.

Both have a 1.33v, but i thought i would add both speed for you, try with the first, then overclock to 760, if it's stable, then flash the second and you'll have it without the need to use Overdrive .

I flashed mine with 878 core and 999 mem speeds, much easier, but kept the voltage default cause i'm using a hard volt-mod, didn't want to screw that up.


EDIT: by the way, i didn't modify your BIOS to pass the 860MHz limit, i can't do that, that fix is from AMD, no-one does it, i think there's a 512MB BIOS that doesn't have this limit here on this forum, don't know if you tried it yet or not, i'll try to get it and link it for you here.

EDIT2: Here're 2 additional BIOS' i found, the HIS one is v071, which is the same version as the one i'm using on my card, but for the 256MB, doesn't have that 860 limit.

The second one is older, v070, but adds an alternative for you to test with, not sure if it doesn't have that limit.

Also, the reason why a BIOS won't work for you is the RAM rating, or brand ... etc, that's why i modded 2 more for you.

Hope one works .

[GenTarkin]

Here's Stilt's BIOS, 862 limit fixed, 1.327v (3870's voltage), and already clocked at 760 core ...

760830-1327v-v071


EDIT: by the way, this BIOS isn't 100% as he gave it to us, i changed it to give more voltage and have more Core speed!

does CCC - overdrive still work properly w/ this BIOS?

[Clint]

I don't get it, why not sharing the tool for modifying the bios...or make a how-to?

This creating of bioses to rigth and left is kinda silly, just give some hints on how to do it instead.

[MonsterMash]

I don't get it, why not sharing the tool for modifying the bios...or make a how-to?

This creating of bioses to rigth and left is kinda silly, just give some hints on how to do it instead.

You're right!

[os008]

does CCC - overdrive still work properly w/ this BIOS?

No, it's screwed up, that's why i used Rivatuner to get stable clock, then write it inside the BIOS and flash it and get rid of the hassle.

I don't get it, why not sharing the tool for modifying the bios...or make a how-to?

This creating of bioses to rigth and left is kinda silly, just give some hints on how to do it instead.

Silly? was i wrong to help someone? didn't get the idea of making a tutorial, not good at it, so i just posted the BIOS' for testing, not going to it again anyway, those are all there is to modify.

Anyway, it's not that hard, ... start HxDen, search for BE04 as Hex Value, press F3 to search again, and you'll find yourself at a distinctive pattern.

HxDen Editor

Let's say you want to change the voltage from 1.2 to 1.3 ... open up the windows Calculator, set it to Scientific, then Hex, then write 04BE, then press on Dec, should give you 1214, that's 1.214v, to get 1.327, then write 1327 in Dec mode, then switch to Hex, you'll get 52F, reverse it, so it's 2F05, now write that number instead of BE04, as easy as that.

For frequencies, you'll find 540501 on the same line of the voltage to the left, if you don't see 54, you'll find it just at the end of the line above it to the right, that's the number for 669 core frequency, reverse it ... 010554, and convert it ... 66900, that's 669.00MHz, write 76000 ... 128E0, reverse it ... E02801, write it in place of the frequency inside the file, again, as easy as that.

Just got it by experimentation, and bits of info from here and there, note that i don't know ANYTHING about how to calculate Hex values, or why do i have to reverse them, or why do i have to keep the middle number fixed ... etc, i just managed to get something going that i need, i don't care to understand how it works, as long as it works.

The second program is for comparing files in Hex mode, i use it a lot because sometimes i forget where the pattern is if i changed the voltage for example, all i have in my memory is BE04, so i open up the original BIOS, compare it to the one i changed, then search for that Hex, and i get where i want to be.

Hex Compare

Hope it helped.


EDIT: Here's a link explaining the same thing, but in what seems to be Yoguslavian or something (guess so from the address).

http://www.benchmark.co.yu/forum/sho...d.php?t=150149

[saaya]

so your editing the bios and the checksum not matching anymore after you edited it... doesnt matter? i thought you cant flash a bios without matching checksum or the bios wouldnt work...

[KainXS]

Here's Stilt's BIOS, 862 limit fixed, 1.327v (3870's voltage), and already clocked at 760 core ...

760830-1327v-v071


EDIT: by the way, this BIOS isn't 100% as he gave it to us, i changed it to give more voltage and have more Core speed!

my card still freezes around 840 and the mem overclocks worst with this bios, can't go over 1050 with this bios, I could go to 1179 before

[chp]

Here's your BIOS modified.

By the way, the BIOS i posted above is for the 256MB version, sorry about not mentioning so before!

Yeah, Yes... os008, It WORKS...... I'm Happy.
Finally I'm able to push my clocks up to 790Mhz for the Core and 999Mhz for the Mem. Very Good Work