Vmod 3850 through BIOS apparently IS possible....

[robbot]

hi

i have got a hd3850 256MB made by sapphire.

I tried to flash bios 760830-1327v-v071 but i couldn't wrote it

Atiflash didn't recognize anything (bios have got a strange .bin extension ) and i didnt want to risk...
7701000a.zip works fine for me.

And there is a difference between this 2 bioses
7701000a.zip - 62 464 size
760830-1327v-v071 - 65 536

... whats wrong ?

Can somebody modify bios for 256 MB 3850 ulocked and rised voltage and pos it here ?

[Chukundur]

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!

I measured 1.288V with this BIOS. On the original one the measuring is 1.240V. With orignal I can get core 730 stable, with this one 756 stable.
Can you make the same one BIOS, but 1053MHz Mem in 3D, for me, please.

[robbot]

can anybody answer for my questions above ?

why there is difference in files size ?
why atiflash didint recognize the secend one bios file

[GenTarkin]

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.



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

Thanks for that guide =) I tried your modified bios the original one and I Still think we need some sort of checksum fix on these...cuz when I flashed with yours, the vendor id..product name...bios version fields were blank.....(result from atiflash proggy) when I rebooted...black screen so I flashed back to 7701000a I posted earlier...that one does have the proper information in those fields.
I tried modifying my own also based off the 7701000a and...when I did the same as above same result all atiflash fields were blank and black screen...so flashed back to original 7701000a bios.
Is there any way to find out the proper new checksum for our edited bios's and apply that too the file?

[os008]

Getting the file checksum is easy i think, not sure, but if you open HxDen and highlight the whole file, then go to Analysis (menu), then Checksum and choose the 16-bit Checksum, you'll get a number at the bottom.

We need an expert to tell us if that's the 'right' checksum, or the needed one, and how to apply it in the first place to the file, tried looking for any command in ATiWinFlash but couldn't find one, actually i found some Checksum related commands, but they're cyptic to me.

Anyway, i'm glad i could be of some help, good luck.


Note: don't know why you're getting blank screen, but i tried a lot of BIOS' with forced flashing, and they all work as long as they have the right memory size (256MB).

[robbot]

can u explain why this 2 bioses had got two different sizes ?

i think that here is the problem . one of them works fine (7701000a.zip) another 760830-1327v-v071 (blank screen )

[Clint]

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.



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

Excellent!

Thanks for taking the time to throw that together!

I did not mean that you in particular were silly, more the fact that there are 3 or more persons making custom bioses but no info on how to do it.

[os008]

Hehe, it's cool, i just wanted to help, i never wrote a guide, and i'm so bad at explaining stuff (as you might have noticed :P), but glad i could help.

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

I didn't change any memory timings or voltages, i just modded the core frequency and voltage for it as Stilt posted it.

As for the core, might be because you haven't hard volt-modded your card yet, if you did, then might be because it's over-heating, happened to me around 904, that's why i'm stuck at 878 for now, can't go higher without crashing cause of heat!

can u explain why this 2 bioses had got two different sizes ?

i think that here is the problem . one of them works fine (7701000a.zip) another 760830-1327v-v071 (blank screen )

The BIOS i modded is Stilt's, it's a 'newer' version, that's why it has a different size.

I don't know why is it giving you a blank screen, it worked for me, and for Chuk, and Chp too.

I measured 1.288V with this BIOS. On the original one the measuring is 1.240V. With orignal I can get core 730 stable, with this one 756 stable.
Can you make the same one BIOS, but 1053MHz Mem in 3D, for me, please.

It's attached to this post Chuk, and to avoid locals running after me with torches, i won't post anymore BIOS', use the ... 'guide' :P ... i posted in this thread please.

Thanks.

[KainXS]

anyone check their GDDR3 max rated freq yet

[goranm]

can u explain why this 2 bioses had got two different sizes ?

i think that here is the problem . one of them works fine (7701000a.zip) another 760830-1327v-v071 (blank screen )

Hi! I can explain it.

Here is the necessary:

1. Latest version of atiflash program.

It is used to “load” BIOS file from card and to flash edited bios.

2. Any hex editor

It is used to change certain HEX values in BIOS

Make bootable USB disk with ATI flash on it. After booting, start the ATI flash using command "atiflash -s 0 bios.rom"
Go back to Windows and load the bios.rom
Open the Overdrive section in Catalyst CC and look for def. clock values for 3D ( it is usual 667Mhz). In BIOS everything is written in HEX + backward. Frequency values are written with 5 characters (before HEX interpretation), and voltage values are written with 4 characters.

For example 669Mhz as 66900, 1150Mhz as 11500, and voltage 1.21V as 1210.
Open the base converter in HEX editor (if you use this editor), or you can use Win calc. Enter the 66900 in calc and (we are looking for 3D GPU value in BIOS) and convert it to HEX (we need 3 pairs of two caracters).

66900 (dec) -> 01 05 54 (hex)

Now we are looking for inverted HEX value in BIOS. We are looking for 54 05 01 (i.e. 669Mhz).

In ASUS 3850 256MB BIOS it is located at address AAE8 (just behind the memory speed value) – we are not interested in this row (if you change any of those two values, catalyst will no longer recognize the VGA, it will be standard VGA), and in this table, little lower, at address ADBF to AE4F. MEM speed value is just beside GPU speed value, followed by GPU voltage value.

Here is how it looks in HEX editor



When complete table is copied in Excel, and we rearrange it a little, it looks like this. You can notice that all values are written 10X – 2D, 3D, overdrive, limits, UVD, thermal throttling? … Does anybody have it documented?


Now the question is: Which value to change? After thirty or more attempts best result is obtained by changing the 4th and 7th value in table, i.e. line 8th and 14th in Excel. By this way Overdrive limits are unchanged, and overdrive runs normal, 2D stays on default, and memory is not at its limit in 2D.
Here is the Catalyst CC def. look after BIOS mod:


I have used unchanged 2D at 300/892, for me, and changed 3D at 750/100 (def. is 669/829), and changed 3D GPU voltage from 1.214V to 1.327 V.

300MHz - 30 75 00
669MHz - 54 05 00
750MHz - F8 24 01
770MHz - C8 2C 01
1GHz - 10 27 00
1.05GHz - 04 29 00
1.1GHz - F8 2A 00

1.014V - F6 03 (2D for 3850)
1.214V - BE 04 (3D for 3850)
1.241V - D9 04 (2D for 3870)
1.327V - 2F 05 (3D for 3870)

Save it as ocbios.rom and copy it to USB bootable disk.

After booting, flash it to VGA using the command "atiflash -p 0 -f ocbios.rom"

7701000a.rom is with changed 2D voltage to 1.241V to improve OC.

[Chukundur]

It's attached to this post Chuk, and to avoid locals running after me with torches, i won't post anymore BIOS', use the ... 'guide' :P ... i posted in this thread please.

Thanks.

Thaks a lot. I apologize, but alreday try to modify mine bios (probably not hard enough) without success. So, what voltage did you measure on your card? It should be 1.327V with this BIOS, but I measired 1.288V?!

[os008]

I never measured it when i soft volt-modded, after testing that BIOS i just hard volt-modded then flashed the 878 speed one i made for myself after making sure it's stable at that speed, used 1.4v for it.

But if it's stable at that voltage then it might be just a v-droop, or so they call it, though, i only heard about it related to Motherboards, don't know about VGA, it's not necessarily and bad thing, but anyway, to get more voltage you have to hard volt-mod.

Download the BIOS i made for you again please Chuk, i editted it, i made a tiny harmless mistake before, but corrected it, if the first one is working then nevermind .

[Eldonko]

os008, do you have a copy of the 512 unlocked BIOS modified to use the extra voltage?

[Clint]

This is very interesting!

So the 3850 has a 2D value of 1.014V ..and the 3870 1.241V ?

They both run at 300MHz in 2D, so why can't we have the lower value on a 3870?

If I try edit the bios to my 3870 and the voltage for some reason is to low, would that mean that I can no longer boot up the card again...meaning bricking it?

[goranm]

This is very interesting!

So the 3850 has a 2D value of 1.014V ..and the 3870 1.241V ?

They both run at 300MHz in 2D, so why can't we have the lower value on a 3870?

If I try edit the bios to my 3870 and the voltage for some reason is to low, would that mean that I can no longer boot up the card again...meaning bricking it?

My 3850 256Mb is running on 1.014V in 2D, and it's flashed to 770/1000 for default clocks. I think that 3870 must run at 1.014V in 2D. It's better GPU (XT version) and it must be capable to run at lower voltages + it's PCB is much better than PCB for HD3850.

[Clint]

My 3850 256Mb is running on 1.014V in 2D, and it's flashed to 770/1000 for default clocks. I think that 3870 must run at 1.014V in 2D. It's better GPU (XT version) and it must be capable to run at lower voltages + it's PCB is much better than PCB for HD3850.

Yes, this sounds logical.

I will try tomorrow, hopefully I get a much cooler card when idle

[Chukundur]

..
Download the BIOS i made for you again please Chuk, i editted it, i made a tiny harmless mistake before, but corrected it, if the first one is working then nevermind .

You made 105.3Mhz instead 1053.0MHz. I already found how to edit the BIOS, and made mine own. Thank you anyway.

[os008]

os008, do you have a copy of the 512 unlocked BIOS modified to use the extra voltage?

I don't, sorry Eld, try to look for a BIOS version 071 and above, did you check your BIOS version?

[robbot]

So finnaly

can anybody modify bios
7701000a.rom

extra voltage on gpu (like 3870 ) + ulocked ?

i will be very grateful

[goranm]

So finnaly

can anybody modify bios
7701000a.rom

extra voltage on gpu (like 3870 ) + ulocked ?

i will be very grateful

7701000a.rom is modified ASUS HD3850 256MB BIOS with changed 2D&3D voltages (from 1.014V/1.214V to 1.241/1.327V) and changed def. 3D GPU and memory clocks from 669/829 to 770/1000.

[STEvil]

someone should compare a limited bios and 071 bios to see what the fix is.

[os008]

Hehe, i did as soon as i got it Stevil, that was 3 days ago i think, and there were way TOOOO many differences, but maybe someone more professional in this matter that can spot the 'real' differences setting aside the offsets.

[robbot]

why the 2d voltage is changed ? what for ?

so now mayby someone can unlock this bios ? becouse my hd3850 works ok on standard voltage when 770mhz is on gpu... an i couldn't oc more becouse lock..

[saaya]

os008 and goranm, great work!!!

[goranm]

why the 2d voltage is changed ? what for ?

so now mayby someone can unlock this bios ? becouse my hd3850 works ok on standard voltage when 770mhz is on gpu... an i couldn't oc more becouse lock..

Lock? What lock? I use RivaTuner 2.06 for overclocking? Why? Because when I OC it from stupid CC maximum is 770Mhz, and GPU frequency is changing during 3D tests because GPU is reducing it's frequency when GPU load is under, lets say, 80%. You can notice this in Riva Tuner when you OC unmodified card (667/826). It drops to 669/826Mhz (2D clocks) when GPU is waiting for CPU or when it's limited by refresh rate. When you OC it with RT it is rock solid at given frequency, because RT can't separate 2D and 3D. Take a look at HD3850 with unmodified BIOS. Same is happening with modified 3850 when you OC its memory above 1000Mhz from CC (def. for modified BIOS is 1000). If you OC it to 1050 it will drop to 1000. GPU limit from CC is 770MHz. Riva Tuner 2.06 solves these problems, and can go 800+ for GPU. That's the most important reason to set 1.241V in 2D or it will crash in 2D during OC.