HD4850 BIOS thread

[xoqolatl]

This thread could serve for HD4850 BIOS editing discussion.
I have seen two bioses so far, one is version 011.004.000000 (6 zeroes omitted on purpose) and the other is 011.003.029117.

In 011.004 clocks are at offset 0000ACD0 starting with two last bytes for core clock.
I am particularly interested if anyone has modded his bios with clocks higher than Catalyst Overdrive allows, and if anyone has newer bios than 011.004.

[alexio]

http://rapidshare.com/files/124638004/HD4850-1327v.rar.html

This BIOS is completely stock in terms of clock frequencies but it has 1.327v in 3D mode. The checksum is fixed, but I have no card to test it with. It shouldn't wreck your card, but I can't be 100% sure. The modding is spotless at least :) My prediction is that this bios may give 1.28v real vGPU because the PWM of this card is so similar to that of the HD3850. ATI uses some odd value for 3D vGPU that makes no sense. It could be that the driver normally controls vGPU in 3D mode and that odd value tells the card to listen to the driver. Maybe my mod overwrites this 'feature'.

What is the Overdrive limit with these cards?

[alexio]

What clock would you like by the way?

*edit* The odd stock 3D vGPU value is completely normal, it was also like that with the HD2900XTs (and HD38**s?). My 'hard' value should just overwrite it.

[gurusan]

I'll try your bios in a few hours, busy at the moment

[xoqolatl]

Overdrive limit is 700MHz. I'll try modding mine with 715MHz later today.

[gurusan]

so have you located the correct area to modify in the bios with hexedit? I am a bit of a newb and couldn't find the area of the bios that controls clocks or voltages

[alexio]

Sure, but keep a PCI card ready in case something goes wrong and set PCI GFX priority in your motherboard BIOS (default setting). http://rapidshare.com/files/124651401/HD4850-1327v-750.rar.html

I suggest you try the other BIOS first though. There's a good chance that in the process of modding I changed the boot-up GPU frequency as well (I changed all the full-frequency profiles including performance 3D and UVD, but possibly also the boot-up frequency, there is no way to know for now!). If the vGPU mod actually works this isn't a problem because at 1.327v the GPU should easily boot at 750Mhz. Now if it doesn't work there is a chance that the card doesn't make it to windows where the drivers takes over and tells the card to run at 2D clocks. If this happens the card won't get damaged, but you do need to reflash it and probably with a PCI card as the HD4850 might be too unstable to flash.

[gurusan]

I have a spare 3850 here and also I'm a fairly proficient blind flasher ;)

I will try the first bios you posted first....

[gurusan]

ok I just tried it but I was stupid and forgot to see vGPU before the flash :/

After the flash I get 1.06v idle and 1.16v full load

[alexio]

ok I just tried it but I was stupid and forgot to see vGPU before the flash :/

After the flash I get 1.06v idle and 1.16v full load
That doesn't look good :( It would be helpful if you flashed it back and checked stock vGPU. There's always a chance of a measuring error. I reckon it doesn't clock any better now, or did you previously run into the 700Mhz Overdrive wall already?

[gurusan]

I'll flash back and see what I get....and yeah CCC won't let me go past 700mhz, which I could already do before the flash

[gurusan]

yup, flashed back to stock HIS bios and still get 1.06v idle and 1.16v load.

[alexio]

Maybe the 3D vGPU value is just complete BS. It is possible that the driver controls this value nomatter what the BIOS says. Maybe AMD chose this approach to make it easier to sell these pre-overclocked cards without the need to change vGPU in the BIOS. Later I'll make a BIOS with a lower vGPU (say 1.24v for example). it could be that the 'high' value of 1.327v could not be recognized. If that fails it's time to start fiddling with device Ids.

[gurusan]

well i have good news.

I have just done a pencil mod and it is confirmed working....it's 1.16 idle now and 1.24 load. will post a pic in a second

[gurusan]

So now that I have increased voltage, a bios flash to 750mhz would be nice :)

http://img110.imageshack.us/img110/2151/4850core2lh9er5.jpg

[DemonEyez]

Great news concering those OC biosses:

Toronto (Canada) – AMD is preparing an answer to Nvidia's recently released GeForce 9800GTX+ card. Overclocked Radeon 4850 cards are set for an introduction in the second week of July.
...
Now we hear that ATI has removed all overclocking restrictions, giving add-in board (AIB) partners more room for new products. Our sources indicate that vendors are preparing a second wave of cards that will feature higher clocks for the GPU and the memory.

Senior ATI officials told us that “4850 Overclocked” cards are likely to come with a core that is clocked about 50 MHz higher, while the GDDR3 memory will be clocked to get at least 5-6 GB/s of bandwidth. Cooling will also change. Pre-announcements indicate that overclocked cards are on their way from companies such as HIS, Sapphire and Diamond.
...
As a side note, we also learned that the Radeon 4870 will not be tied down to its default clock speed for very long. We heard that at least one AIB vendor is preparing an overclocked 4870 card.

Source:
http://www.tgdaily.com/content/view/38077/135/

[gurusan]

hopefully these are out soon. i need to clock my 4850

[gurusan]

So I changed the 3d clocks in my bios using a hex editor....but it will still only show up as 700mhz !! even when I put 740mhz into it. I'm pretty sure I'm changing the right values as my default clock is now 700mhz.

[xoqolatl]

It looks like another clock limit like with early 3850 bios.

[gurusan]

lameness. I hate being patient.

[gurusan]

is there something in the bios that controls the CCC max clocks? or is that controlled by the drivers?

[Errik89]

there is any chance to see new version of bios editors in a short time?
and how can I see the actual 3D vGPU?

[xoqolatl]

there is any chance to see new version of bios editors in a short time?
and how can I see the actual 3D vGPU?
Measure it with a DMM.

I just noticed a difference between 011.003 and 011.004 bios: 011.004 has different clock states, especially 160MHz core/500MHz memory when in 2D, as opposed to 500 core/750 mem in 011.003. Editing 011.003 to these values seems to have no effect. It also seems that Powerplay is working correctly with this bios and 8.6 hotfix drivers. I'll try to measure the power consumption and confirm that.

[DemonEyez]

xoqolatl, could you post or upload your 011.004 bios? And what brand HD4850's do you own?

*edit*
I took look in the bios collection on Techpowerupcom and found an MSI HD4850 011.004 bios, it also has the lower 2d state of 160/500:
http://img529.imageshack.us/img529/1094/versie4lr9.jpg

[gurusan]

powerplay seems to be working fine, my card is at 750/1100 at the moment with 1.23v

[DemonEyez]

powerplay seems to be working fine, my card is at 750/1100 at the moment with 1.23v

??? how did you get 750Mhz :eek: :clap:

[gurusan]

disabled overdrive, pencil modded...edited the bios with a hex editor...and flashed :)

I am just going to hazard a guess here, but I think the 4870s may not even be higher binned than the 4850s...since my stock voltage is 1.16v under load....it seems low. I'm almost willing to bet the 4870s will be running 1.2ish under load for 750mhz

[DemonEyez]

Sound very promising! :)
Is there a comprehensive guide on how to edit the bios to, for example, 750MHz?

How did you enable Powerplay? Did you edit that yourself also or did you take a 011.004 (which has Powerplay already enabled)

Will be doing the pencil mod myself this evening. Already performed the VR-volt mod last evening, but I'm out on 100K VR's so everything is soldered, only thing missing is the VR... :(

[gurusan]

I didn't touch powerplay, I only edited the numbers I thought were 3d clocks in the bios.

I just used a hex editor to search for the 2d memory clocks (750mhz). The bios uses 75000 to indicate 750mhz, so using calc.exe convert 75000 to hex and you get 124F8.
Now for some reason it lists these values backwards in the bios....so you search for F8 24 01 (124f8 backwards).

http://img124.imageshack.us/img124/1537/89266956ui5.jpg

Now if you convert some of the numbers around these you will see familiar clocks like 625mhz (3d clock)....do some converting for a bit and you will a pattern and recognize a table of clocks.

http://img205.imageshack.us/img205/4180/77869111na3.jpg

Now convert the appropriate numbers to your desired clocks, for example for a 750mhz clock use calc.exe to convert 75000 to hex, and replace the 625mhz hex values. Remember to do it backwards!

So afterward it would look like this:

****WOOPS i made a mistake...the bottom row should begin with F8 not 58 :p *****

http://img156.imageshack.us/img156/6883/24187583hr5.jpg

Now save your bin as another file so you don't overwrite the original. By editing the bios you have changed the checksum...so your card will probably be borked if you flash it with the bios as it is.

To fix this read alexios tutorial:
http://www.xtremesystems.org/forums/showthread.php?t=180607&highlight=checksum

[Devious]

thanks for the info :)

[DemonEyez]

Thanx for the elaborate explanation gurusan! :up::up:

For those who don't want to mess with hex keep an eye on this topic on Techpowerup:
http://forums.techpowerup.com/showthread.php?t=54776&page=11

Wizzard wrote:
RBE supports 48xx fan control and overclocking now. Expect a release in the next days
:D

disabled overdrive, pencil modded...edited the bios with a hex editor...and flashed :)

I am just going to hazard a guess here, but I think the 4870s may not even be higher binned than the 4850s...since my stock voltage is 1.16v under load....it seems low. I'm almost willing to bet the 4870s will be running 1.2ish under load for 750mhz
it seems that the HD4870 is running with vgpu 1.263v according to this submitted bios:
http://img160.imageshack.us/img160/727/4870ba8.jpg

[gurusan]

good news to hear regarding RBE :)



And 1.263V.... :) so it looks like maybe I was right.

[JamesBong420]

i hope you all are looking in this thread..

http://www.xtremesystems.org/forums/showthread.php?t=192411

:up:

[Errik89]

very good news about the new versione of RBE!!!!!!!!!!!!!!!!!

I was waiting that!!! :up:

[GAR]

So im new to ATI, what is powerplay, also is a bios voltmod possible?

[albon]

Newest 004 MSI 4850 bios modded to 725/1050 with RBE (s2-m3 and s4-m1 modded), so you can keep 160/500 on idle.
http://dl.free.fr/cRs3nPShs/msiOC725-1050.rom

[fatbird2046]

"By editing the bios you have changed the checksum...so your card will probably be borked if you flash it with the bios as it is.

To fix this read alexios tutorial:
http://www.xtremesystems.org/forums/...light=checksum"

Thanks for sharing with us!

But....What kind of cheksum algorithm should we care?

There are so many algorithms from "checksum-8" to""sha1" in Hex Workshop,whichone should we care??CRC-32?

======It's Checksum-32.Problem solved！！Thank you all very much！

[cool_recep]

Hi guys,

who wants to give it a try to the latest* Toxic HD 4850 bios?

*Original Toxic BIOS was updated.

Edit: As i have seen, the new Toxic BIOS has 1100 Mhz RAM while the old one had 1150 Mhz.

http://rapidshare.com/files/133166787/ATI.rar

The file contains: ATOMBIOSBK-ATI VER011.004.000.000.000000 Sapphire Toxic HD 4850 BIOS

SS's of the HD 4850 and HD 4850 Toxic BIOSes for easy comparison.

BTW: I have a question. What happens if i flash my HD 4850 with the Toxic BIOS?

Thanks.

[Viilutaja]

Hey. I have a Sapphire HD4850 card. I measured vcore with DMM and it was 1.10 v. only under load. Is that normal? At idle, it's like everyone else has.

[HousERaT]

Hi guys,

who wants to give it a try to the latest* Toxic HD 4850 bios?

*Original Toxic BIOS was updated.

Edit: As i have seen, the new Toxic BIOS has 1100 Mhz RAM while the old one had 1150 Mhz.

http://rapidshare.com/files/133166787/ATI.rar

The file contains: ATOMBIOSBK-ATI VER011.004.000.000.000000 Sapphire Toxic HD 4850 BIOS

SS's of the HD 4850 and HD 4850 Toxic BIOSes for easy comparison.

BTW: I have a question. What happens if i flash my HD 4850 with the Toxic BIOS?

Thanks.
I've seen at least one review with the Toxic card and it had Samsung memory so keep that in mind. ;)

[drizzt5]

I just purchased a asus 4850 off of newegg and it's otw to my house. Can I use the radeon bios editor here
http://www.techpowerup.com/downloads/Utilities/RBE/
safely with my 4850 without using a multimeter?

I was considering a pencil mod eventually once I have a multimeter to use.