May my hours of toil this past weekend save you frustration. This guide is most likely applicable to many other models. The whole reason I did this is to get a consistent clock speed without having to muck with Catalyst Control Center or other garbage programs. The EAH4870 I just bought from NewEgg is a pain in the ass, as it creates some weird lockup issues when changing clock speeds for "2D" and "3D" modes...

Step 1: Go to this link:

http://wccftech.com/forum/overclocking-modding-benchmarking-and-tweaking/1970...

Grab the tools you need, which you can find in this thread, to make a DOS-formatted USB boot disk.

Step 2: Download GPU-Z.

http://www.techpowerup.com/gpuz/

This is a handy utility for monitoring your graphics card - but more importantly - dumping the BIOS. Dump the BIOS using the little tiny icon and save it in a special, hallowed place.

Step 3: Download Radeon BIOS Editor

http://www.techpowerup.com/rbe/

You can use this to set clock speeds, fan speed, etc. Read up in this thread before you do ANYTHING. This is dangerous stuff.

http://www.techpowerup.com/articles/overclocking/vidcard/154

OK, now that you know RBE inside and out, create a BIOS file with the settings you desire, then save it to the USB drive.

Step 4: Download ATIFlash

http://www.techpowerup.com/downloads/1731/ATIFlash_3.79.html

Download this program, ATIFlash, and copy it to your flash drive.

Step 5: Boot from the USB Flash Drive

Assuming the drive boots properly (you may need to edit your motherboard BIOS) run the following command:

atiflash -i

You will see your graphics card device listed, probably at location "0," unless you're running multiple cards. I don't have multiple cards, so I had just one device in location 0. I then ran this command:

atiflash -unlockrom 0 (If that doesn't work, switch the parameters around, but I think is correct)

This command is CRUCIAL. It unlocks the BIOS ROM in the card from protection so you can reflash it. You should get an "Ok" if this worked correctly.

Then, run

atiflash -p 0 "yourrom.bin" (replacing with the name of your ROM file, removing quotes)

The flash should then work properly. You should NOT have to use the "-f" switch to force the upgrade. I'd worry about your ROM if you had to use it.

You're welcome.

(If this didn't work, do more research on your individual card and on the Internets. Google is your best friend. Don't blame any of the awesome programmers who created these tools if you brick your card, it isn't their fault...)