Printable View
I flashed my Powercolor 3850 512MB with the sapphire bios from "the-strokes" but my voltage remains the same (1.28v 3D) :( the BIOS does nothing but creat an 2D profile with 297Mhz core and 1.24v. With the stock bios, the card runs constantly at 720MHz and 1.28v for both 2D and 3D.
i just flashed to the bios from the-strokes.Quote:
Originally Posted by eva2000
i had to installed the drivers again, meh...
well for once, the original bios i used had much higher 2d volts and it had the same clocks in 2d as in 3d.
same as on the powercolor card from ken. it seems powercolor and club3d cards are the same, except for some powercolor cards using quimonda mem... well maybe some club3d cards also use quimonda?
here is how i meassured vgpu:
http://www.abload.de/thumb/vgpuerf.jpg
with the attached sapphire 512mb bios i get:
IDLE:
with the first one i get 1.251v
with the second one i get 1.280v
with the third one i get 1.252v
LOAD:
with the first one i get 1.298v
with the second one i get 1.323v
with the third one i get 1.298v
with my original bios i had 1.33v/1.40v vgpu under load!
so much better than this.
here ken, try this bios, im sure itll give you a little gpu boost since it has higher vgpu :)
thanks for uploading saaya but your bios completely messed up my card, got corrupted screen after flashing so I had to do a blind flash :p:Quote:
Originally Posted by saaya
I think its the difference in ram parameters that caused the problem since your Clud3D uses samsung and my powercolor uses quimonda :(
Dam, wish that worked, I want that extra vgpu! Well maybe Ill just hardmod..
check out the techpowerup vga bios database, there are a few 3850 512mb bioses with different voltages :)
the weird thing is... i am stuck at the same gpu clocks with this bios with lower vpgu as with my original bios with higher vgpu! 0_o
so does my gpu suck THAT bad? :D
I couldnt wait so I decided to mod the bios myself as below:
http://img57.imageshack.us/img57/3831/kmodox6.png
I now have separate 2D(300MHz) and 3D(720MHz) clock but the voltage still remains at 1.28V in 3D :(
did you check the voltage values in my bios?
maybe you can copy paste them into your bios? :D
I checked up your BIOS and found this patternQuote:
Originally Posted by saaya
http://img227.imageshack.us/img227/4507/sayaaal7.png
the core and mem clock seems to follow the findings of "Janchu88" here: http://www.xtremesystems.org/forums/...d.php?t=167966
(40 19 01 = 72000 = 720MHz ; 90 5F 01 = 90000 = 900MHz )
but the voltages are just weird :p
CE 03 = 974 = 0.974v
FC 03 = 1020 = 1.020v
C4 04 = 1220 = 1.220v
so I have no clue how you got over 1.3v when measured :confused: from table it seems your 3D voltage is only 1.220v, maybe thats why you cant go over 760? :p:
in my modded BIOS, i have 2F 05 = 1327 = 1.327v but it only gives me 1.28v in 3D for some reasons:(
i used the same value (2F 05) in my sapphire bios and it's also giving me 1.274vQuote:
Originally Posted by ken
weird... can you mod my bios to 1.327v and post it here?
id like to try it and see if i get higher vgpu readings.
im starting to think the vgpu reading spot is wrong... or maybe it only works properly on the reference design? or maybe the card layout adds a certain voltage to the voltage programmed in bios?
i meassured the smd caps on the back of the gpu and im reading roughly the same voltage as at the vgpu reading spots...
I use the same spot to measure the vcore and it reads 1.28v with all the bios Ive tried.Quote:
Originally Posted by saaya
btw, here your modded bios, I only changed the 3D voltage (to 1.327v - 2F 05) and the clock of the first set to match with your current clock. Please dont blame me if anything happen to your card because Im new at this as well :p:
hex compare of your stock and modded bios
http://img149.imageshack.us/img149/7493/saayaiw3.png
Saaya did you try this mod yet?
Ken did you try it?
Ive tried every possible way but none has worked so far :( voltage stucks at 1.28v for 3D. Maybe hardmod is the way to go :p:Quote:
Originally Posted by MsB
I just need a bios that will allow it to oc past 760/1850 and I will use the pencil mod. I tried it on one of my cards and with riva got it easly to 800/1800 but Im stuck at 760 with CF
MsB, tried my stock HIS HD3850 IceQ 3 Turbo bios stock is 715/909 and out of the box i am running 2x of these in CF a 783/1100
Bios http://fileshosts.com/videocards/HIS...iceq3_bios.rar
i guy sorry for my bad english,i'm a frogman
i have a problem i have testing x bios and zero good
atiflsh=error 0fl01 and atiwinflash error subsystemID for all bios:confused:
fairdell hexcmp is hard for me:(
one pro for look my bios and mod for clok the vlt for over 800/1000 please?
it's possible? thanks you very much!!:up:
sapphire HD3850 512
http://www.fileshost.com/en/file/233...k3850-rar.html
hey chabalou,
Welcome to XtremeSystems :toast:
frogman? you mean your french? heheheh dont be so hard on yourself! :D
Im going to try the modded bios now, thanks a lot ken! :toast:
tanks saaya for your "accueille" :D
yes i'm french,no kick my ass,no kick my ass please!! :slapass:
i looooove the queeeeen...or...not :D joke
happy christmas thanksgiving and co all :toast:
oh guys, you're starting to play hard I see....i can't understand a number or a letter in that bios.....:D:D
0FL01 Error programming ROM (from atiflash troubleshooting guide)Quote:
Originally Posted by chabalou
----------------------------
- Check that the command line arguments you passed are correct.
- Check that the BIOS image file specified exists and isn't corrupted.
- Check that the ROM isn't write protected.
- If a parameter in the BIOS image file differs from a parameter in the
current ROM image (e.g. SSID), and you're sure you want to program
the image, specify the -f (force) flag on the command line.
did you use the " -f " when flash to force flash? I got the same error when I didnt use it. There is modded Sapphire BIOS in saaya's few posts back you can try :)
p/s: I can have a look at your BIOS and see what I can do but I cant download your file, where to click to download on that filehost site?
@saaya: how the modded BIOS? I hope everything is still working :p:
hi ken thx for look my problem:)
atiflash -f -p 0 newbios is not good..
atiflash -f -p 0 newbios -f not good
yes i testing bios saaya's but not good (sapphire,his,club3d)
There is not a single good for my card :rolleyes:
look for DL my bios
http://img144.imageshack.us/img144/6...ilesic9.th.png
Did you try this one?
hiQuote:
Originally Posted by chabalou
I just downloaded your bios and compared it with the "sapphire3850_124v_133v.zip" and they are identical apart from the voltages
http://img236.imageshack.us/img236/8817/compareqy4.png
so if it doesnt work for you then nothing we can do atm, have to wait for a new solution or do the hardmod
ok ken tanks for your reponse!!
i have test hexcmp huhu^^
go tutorial :D but hard^^
http://img183.imageshack.us/img183/1...rrores9.th.pngQuote:
they are identical apart from the voltages
i not understand /cry
I get an error that says subsystem mismatch with win lfash :shrug: and I cant get this P35 to boot to usb stick :mad:Quote:
Originally Posted by eva2000
Just make sure USB legacy is enabled in your P35 bios. You might have to play around with some boot settings.. most mobos should support it as long as the first boot device is set to "Removable" and make sure that all other devices are disabled.. I dunno for sure.Quote:
Originally Posted by MsB
USB drive shows up as a HD on P35. Set USB drive as HD 1 and set HD as boot prio 1.
I can't get over 850MHz on gpu, I'm using Gecube HD3850 512 OC Edition.
850MHz everything is fine but over it sys crashes ???
with or without mod?
without a mod i can only get 860 stable...
EDIT: my bad! 760 is the max stable without a mod for me!
I am in the same situation, the difference is that I have a Powercolor HD3850 512 PCS.Quote:
Originally Posted by Greg_1
I can play crysis or COD4 for hours at 850Mhz but if I pass 860 I get a system lock.
I made the pencil mod (vgpu=1.38v), so what is limiting my overclock is the bios.
Does anyone have a bios that is unlocked for this card?
@saaya, with mod, without I could get only 750
@Thoth36 after updating gfx bios I don't have that problem any more, now I can get 890MHz but it is unstable on my current V ;)
yeah my bad, it was a typo :DQuote:
Originally Posted by Greg_1
what bios are you using now?
did my bios work or you had to hardmod it? :p:Quote:
Originally Posted by saaya
I'm using bios ver 010.073.000.001, my old bios was 010.067.000.000 I think :)Quote:
Originally Posted by saaya
im in my hometown and didnt have time to try your bios before i came here, sorry :D ill be back in the south in a few days and will give it a try then :)Quote:
Originally Posted by ken
hmmm could you post the bios with the 860mhz fix here? :DQuote:
Originally Posted by Greg_1
I've been unable of finding a unlocked bios for my Powercolor HD3850 PCS 512 mb (qimonda).
BIOS: http://uploadline.com/dline/722975/1...monda.v070.rom
If someone can fix the 860Mhz limit, or direct me to a place where I can download an unlocked one, I would be very grateful.
Here you go :)
It's from GeCube 3850 512 X-Turbo III, works fine above 860, enjoy.
Thanks Greg_1, I tried that bios, and apparently it does not lock the system above 860, but I had to reinstall the drivers (not a problem).Quote:
Originally Posted by Greg_1
Now I'm gonna have to check the voltages, because it was very stable at 850Mhz (1.38v) and when I tried it above 870Mhz crysis crashed to desktop (maybe need more voltage).
Edit:
Bumped the gpu voltage (pencil mod) to 1.46v (3D), and now it's stable at 918Mhz.
Long time lurker
seldom poster, in dire need of help.
I have two sapphire 3850 512mb cards. I cannot find a bios that works for the life of me. Everything is either subsystem IDs do not match or cannot find Vbios image file. I am using ati winflash, because I have flashed my 3870 with it so many times I think the card no longer knows what it is :/
I am looking to unlock it. By the way ATI overdrive limits these cards to 720 :confused: pretty low compare to others. Anyhoot my stock bios is attached if anyone can help out.
If you own an HIS turbo 512 card and havent checked the type of vram, you'll be glad to know its Samsung. Number on the chip reads SAMSUNG 743 K4J52324QE-BJ1A. All i know about that chip is that its very close to 1.0ns by comparing it with other model numbers... havent found any info on them.
Any easy way to tell voltage on vram? Im sure default 3850 volts would be quite limited... OCing to a stable 2000mhz on default vram volts is impressive, but I cant wait for volt tweaking software!
Kinshou Kuma, winflash didnt work for me either... i used atiflash and forced the files to work. thx for the bios greg! ill give that a try as well, hope it works on my card even though i have samsung and not quimonda mem
I didnt get atiwinflash to work the traditional way either.
I tried a work around and it worked. What I did was:
I opened a cmd window (in vista - right mouse click - open as administrator)
Then I navigated (in the cmd window) to the folder where I previously put atiwinflash and the bios file (ex: D:\atiwinflash).
Then typed: atiwinflash -f -p 0 XXXX.rom (where XXXX.rom is the name of the bios file)
Pressed enter, waited a couple of seconds and I received a popup confirming the flash, and asking for a reboot.
In my case winflash worked just fine in the traditional way ;)
Winflash worked for my 3870 but not these 3850s. I will try the above the above method and post back :)
now am getting file not found but I see the file in the folder :confused:
Does it have to the bios for another sapphire 3850 512mb ?
I have a Powercolor HD3850 512MB xtreme and looks like my card does not have a 2d mode. I tried flashing it to a newer PC bios 070 (mine come with 067) also tried a Gecube 073 bios but Rivatunner/ati ccc or Gpu-Z 0.15 don't show a 2d mode, it's always at 3d clocks. Both times i flashed with atiwinflash and i didn't had to reinstall drivers, it only asked to restart.
Another weird thing is i can't overclock with Rivatuner, when i hit the "apply" button it just revert to the default 3d clock...
Can anyone help me on this?
thx in advance
ps: sry if its in the wrong place
Did you type the bios name correctly?Quote:
Originally Posted by Kinshou Kuma
Did you navigated, in the cmd window to the folder where atiwinflash and the bios file is?
This is what I did:
First I decompressed atiwinflash 2.0.0.2a (that includes atiwinflash.exe plus a bunch of other files most of them dlls) to G:\bios 3850\winflash.
Then I copied the bios file to that folder.
Then opened a cmd window
http://img140.imageshack.us/img140/7706/cmdze6.jpg
If you have a sapphire 3850 512mb, that is locked bios ver. 010.070 or previous, and if you can find a bios file for that card that is newer, go with it.Quote:
Originally Posted by Kinshou Kuma
If you cant, then you can try a bios from another brand, but it may not work and in that case you have to be prepared for a blind flash or having to insert a pci card to reflash your 3850.
In my case I flashed my powercolor hd3850 pcs 512 with the gecube one that Greg_1 posted above and it worked.
You can modify your bios to change the 2D settings:Quote:
Originally Posted by zuelber
http://img57.imageshack.us/img57/3831/kmodox6.png
This is one that I modified previously to downclock the 2D clock to 300Mhz and the 2D voltage to 1.014v
Above the original bios and below the modified one.
http://img87.imageshack.us/img87/1545/bios2dez7.jpg
You must also know how to covert dec to hex (simple using the windows calculator in scientific mode)
_BIOS______HEX_____DEC
30 75 00 = 00 75 30 = 30000 = 300 Mhz
40 19 01 = 01 19 40 = 72000 = 720 Mhz
BE 04 = 04 BE = 1,214 Volt
F6 03 = 03 F6 =1,014 Volt
PS: This is what I understood from reading, I am not a specialist. Those are the changes I did and I didnt have problems.
Grrr i have the same problem :( what ever my Vgpu is my card wont pass 870mhz i'am running the 256 Mb sapphire
http://www.xtremesystems.org/forums/...d.php?t=171506
Does your card use Qimonda?Quote:
Originally Posted by Thoth36
I have an Asus 3850/512, pencilled to 1.44kohm. I am afraid to stick my big fingers in there to measure the voltage while the pc is running but from what other people measured, the voltage should be around 1.39. My card is stable at 860-862. When I set 864 it gives me a blank screen or major artifacts right after hitting the apply button which makes me think it's a bios limitation.
I am going to try the bios that Greg_1 posted, unless if it's for Samsung memory.
My Powercolor uses qimonda, and that bios works, dont know for asus.Quote:
Originally Posted by billy79
I modified the bios Greg_1 posted to have 2D clock = 300 Mhz
Bios file:
http://uploadline.com/files/1285653/gc38502D.rom.html
Happy 2008!
another question: why ati ccc only gives me a small range to overclock?
http://img221.imageshack.us/img221/3660/3850sns3.th.png
Quote:
Originally Posted by Thoth36
another quick reply, thx again
should i flash from windows or dos, or it doesn't matter?
oh, and happy 2008 :up:
I think it doesn't matter, but if you flash from DOS you should use atiflash instead of atiwinflash.
Yes, the Asus 3850/512 uses Qimonda as well and yes, I know I am responsible if I mess up the card :D . I'll try your bios tomorrow, b/c by the time I get out of work it will be time to head out for the new years party! (doesn't feel like new years though, 79F :eek: here in Clearwater)Quote:
Originally Posted by Thoth36
Happy 2008 to everyone else too!
sure he-heQuote:
Originally Posted by Thoth36
Well i already flashed and it's working, but i wish the temperature drop could be better than 1ºC lol
http://img245.imageshack.us/img245/1450/38502vm4.th.jpg
now i need to fix that small overclock range ccc gives me
and somehow i can now overclock with rivatuner, btw what's your best stable clocks?
I'm glad it worked.
Been playing crysis at 918Mhz / 1064Mhz(mems), Vgpu 1.46v (measured in the card), load temp ~ 60ºC.
I think the card could reach 1Ghz with a little more voltage. Havent tried yet.
Thanks. It was a typo. I flashed it with the Gecube bios posted by Greg_1 but I got a blank screen. Blind flashed it and then tried the powercooler and blank screen again LMAO once again blind flashed it. took it out. Put my 3870 back in and opted to sell these two cards and get another 3870 lol The 3850s were a gift.Quote:
Originally Posted by Thoth36
is there any software like rabit with 38x0 support ? i find on unlocked bios for my 3850 256Mb and i want to flash with the max frequencys
Kinshou Kuma you were you able to flash them back to their original bios right?
Yeah. I restored the card. I may try again tomorrow. I get a kick out of playing with hardware..its fun to me :p: so I may give it another whirl just cuz it would be cool to have a 3850 xfire beat a 3870 xfire lolQuote:
Originally Posted by Thoth36
wow nice card you have there :)Quote:
Originally Posted by Thoth36
I had to revert to 073 GC bios because many 3d aplications (such as 3d mark) wasn't loading :(
I noticed that 073 GC bios rised my temps like +5º ~ +8ºC at iddle so i flashed back to 067 PC bios and temp went down... then i reflashed to 073 GC and temps are up again... wth??? it's just miss reading or GC bios can add more voltage ?
@Thoth36: do you have the PowerColor PCS 3850 512MB? and which registor did you pencil to vmod?
I just checked the voltages in de GC bios and they are set to 1.214v/1.014v (3D/2D). Dont know what they are in your 067, if you can post the bios I can see and I'll tell you.Quote:
Originally Posted by zuelber
@ Ken - Yes I have a powercolor HD3850 512 PCS (qimonda memory)
The resistor I penciled was the one marked in black.
http://img149.imageshack.us/img149/5293/pencil1ay2.jpg
In this image is the blue one:
http://img88.imageshack.us/img88/2171/img2953jk5tx2.jpg
(these images are not from my card)
witch GC bios you just checked, the original or edited with 2d/3d clocks? I'm asking because with the original 2d/3d clocks are the same for my card.
Yes the GC they have both the same voltages (the original and the one I edited to have 2D clock = 300Mhz)Quote:
Originally Posted by zuelber
2D -> F6 03 = 03 F6 = 1014 = 1.014V
3D -> BE 04 = 04 BE = 1214 = 1.214V
Your v010.067:
2D 1 -> CE 03 = 03 CE = 974 = 0.974V
2D 2 -> FC 03 = 03 FC = 1020 = 1.020V
3D -> C4 04 = 04 C4 = 1220 = 1.220V
My original Powercolor v010.070
2D -> F6 03 = 03 F6 = 1014 = 1.014V
3D -> BE 04 = 04 BE = 1214 = 1.214V
http://img137.imageshack.us/img137/896/compso7.jpg
Thank you!Quote:
Originally Posted by Thoth36
Your bios works on my Asus. I am now able to set clocks above 862 but I am not stable, lacking voltage. Could you edit that same bios for 1.29V for 3D. My latest Asus bios had 1.29V from bios which, with the pencil was giving me around 1.39. Now I can't get that high, and I can't even pass 3dmark06 at 860:( I will keep shading the resistor, but I don't want to loose an easy almost 0.1V from bios.
Your help is much appreciated!!
ask ati/amd :DQuote:
Originally Posted by zuelber
I got a GeCube X-Turbo III waiting for me to get back from my GF's parents place next weekend.
I'm planning on using Greg_1's BIOS on it, I apparently need to do a pencil mod on the card to get to those high speeds, right? How safe / unsafe it's to do without anything to measure the voltages on?
hi Kaotik
Welcome to XtremeSystems and happy 2008! :D :toast:
well in theory you could use the gpu temperature to guess what vgpu the card is running with atm :lol: but.... i wouldnt recommend that.
you should get a multimeter, they only cost 10 euros or so :)
Try this one, if it does not work, dont be mad at me, because as I said before I'm not an expert :)Quote:
Originally Posted by billy79
http://uploadline.com/files/7689659/...2D129.rom.html
Thanks! That did it. I passed 3dmark at 864 core, it failed at 877. It looks like it will require a bit more play with the pencil :DQuote:
Originally Posted by Thoth36
i have a question for you :D anyone who is not on stock coolin system what cooling do you use on the mosfets on the card ? i have vmoded @ 1,56V and while i was running 3dMark i heard on tsafff like one mosfet has exploded but the card is still working ( i used Vga Ram Heatsinks ) now i have one 92'' fan on the :)
Cheers, though I have been registered and reading since 2004 :DQuote:
Originally Posted by saaya
You're right about the multimeter prices, so I guess it's indeed better to be safe than sorry
My card does not respond to overclocking LOL I tried riva tuner 2.06 & newest ati tools, nothing happens ! Clocks r going up (gpu-z) but performance not at all :-D wth ? Procesor Intel 2140@3.0Ghz, 2x1GB OCZ 800Mhz@900, 3DMark2005 - 16000
Asus 3850 512MB
Any suggestions ?
new cpu :D
Not sure if it means this BIOS is unlocked, but I got this card to 860-862Mhz now (according to riva), but crashes at 865.
http://img213.imageshack.us/img213/2078/jan105xq2.jpg
Hey guys..i have a HIS HD3850 IceQ 512mb, bios version xxx.071.xxx, but i can't pass 760 mhz on core, i am afraid to flash the Thoth36's gecube bios in my card because the memory chips aren't the same..I will have problem if i flash my card into that bios ??
Thx for answers :)
I would look for an updated HIS BIOS before flashing other brands, esp if the mem is different. Look thru the thread there are a few posted.
Quote:
Originally Posted by victorbr
That problem is almost certainly, lack of voltage. Mine didn't do much more than that at sock voltages.
Look for a voltage mod for that pcb, pencil mods are pretty easy.
So have the modded BIOSs with stock 2D volts and 1.33v 3D worked well for people? I'd like to get that working because my card spends most of its time idle anyway. Gecube 3850 X-Turbo III here.
Hello @ all,
so i`m new to this forum and i have some questions...
I have a Sapphire HD3850 512 MB (Qimonda) Card with BIOS ver.071 modded to 1,28V in 3D.
In a few days i want to make the hardmod, so i can reach the 862MHz-limit.
1.) The BIOS-file form Greg_1 is the only BIOS without the lock, right?
2.) Which version does it have?
3.) Can i use it on my Sapphire Card?
4.) which version of 3850-BIOS is the latest available?
5.) Could someone please post a picture of a vmem-mod or show me the points that i have to solder?
So long... (and thanks for all the fish ;))
Thx for answers.. i just have checked the memos chips in my HIS IceQ and they're samsung..Can you say me wich bios posted in this topic i can flash into my vga??
Here is a modded BIOS for 3d vgpu on Sapphire 512 MB. Worked fine for me and it is unlocked.Quote:
Originally Posted by R3van
Please..somebody wich have a HIS compatible unlocked bios post here..IceQ Edition is very beautifull for this poor performance :D
There are a few posted in this thread and in this thread.
I have modded my BIOS-Voltages for myself, that is no problem...Quote:
Originally Posted by Eldonko
Thx Eldonko, i flashed my card with Bo-Fox bios, now i can hit 830/2260 :D
EDIT: Ow :banana::banana::banana::banana:in crap!! Crysis crash with every clocks better than 750/2180 ...This game is a HELL!!
No one here can answer this Questions?Quote:
Originally Posted by R3van
@ Revan:
3.) you can, as long as it has the same PCB and memory (timings differ between Qimonda and Samsung memory)
i have modified my Sapphire ver. x.071.x bios to disable 2D clocks and bump the vgpu, I flashed my ASUS without a problem (both Sapphire and ASUS use the same PCB and Qimonda memory)
I have put together a more clear explanation of what you have to edit in bios:
(assuming you have hex editor)
http://www.profide.eu/files/biosmodguide.png
Image is of Sapphire 071 bios, unmodded
after you modded it, did ccc overdrive still work?
No, but I didn't use it anyway because the bar only let me go to 690/850
I can clock with RivaTuner.
so what is actually stopping overdrive from working? this is driving me insane. im running vista x64 with crossfire and there is no other way to oc both cards.
Thanks for the answer but modding my bios is not a problem to me, i have modded it to 789/1089 with 1,33V in 3D.Quote:
Originally Posted by xoqolatl
Why did you disable 2D-Clocks?
But i want to make the hardmod on my card and for that i need a bios that has no lock at 862 MHz (cause my goal are 900 Mhz).
I heard in another forum that all bioses with ver 071 and higher has no clocklimit, is that right?
There's an issue with Crossfire, Cats 8.1 and certain games when second card randomly switches between 3D and 2D clocks while playing, it makes framerate drop severely :( it's always at 3D clocks in 3DMark however.
AFAIK all 71 and up bioses have clocklimit fixed (not present), although I havent seen bios newer than 071 yet.
EDIT: Power consumption with 2D clocks/voltages disabled is roughly the same as with stock bios. When cards are idle (cpu loaded) it's about 230-240W (measured with Zalman ZM-MFC2) no matter what the clocks are.
hi, this is my first post here. I got a Powercolor 3850 512 oced version with cooler zerotherm Pics. I cant pass 770/950 frequencies on driver. Can anyone mod my bios? or post a bios compatible?
sry for my bad english...
ok, thanks.
The Gecube 3850 512 MB has BIOS ver 073, i modded one for someone...
Unfortunately his card has samsung memory, my card has qimonda :(
I got some info on how to keep Overdrive working: (thanks Daedalus!)
http://www.profide.eu/files/biosmodguide.png
As long as you don't change values in the top line (offset 0000ADC0), Overdrive works. But from my understanding, when you unlock overdrive card switches to "Overdrive values" (as oposed to 3D values and 2D values) and vcore & clocks are back to normal. So it's o fno use for us, unless you modify 2D voltage (which seems not to change when Overdrive is unlocked). It'd be much better to find a way to fool the driver to allow Overdrive on any set of Overdrive values (so that starting clocks and vcore are what you set in bios).