HD4850 BIOS thread

[DemonEyez]

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

??? how did you get 750Mhz

[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).



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.



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 *****



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/...light=checksum

[Devious]

thanks for the info

[DemonEyez]

Thanx for the elaborate explanation gurusan!

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

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

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:

[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/...d.php?t=192411

[Errik89]

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

I was waiting that!!!

[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.