UPDATE BELOW IN COMMENTS

As I wrote back here, the Asus EAH5850 card has issues with screen flickers when using dual monitors. This occurs whenever any overclocking utility is used, whether it be the ATI Overdrive or MSI Afterburner. While I might have been satisfied with the slower clock speeds, I got really frustrated when the flickers came back every time I launched Far Cry 2. Also, on boot the flickers were there, and I would have to enter the CCC and enable/disable Overdrive every time I rebooted the system. It was time for a fix.

Since I knew the issue was with the dynamic clocking of the memory on the board, I decided to lock the RAM at 1250 MHz. This is safely below the maximum 1300 MHz that I had achieved in testing, and should still provide a very good boost to games. While I was at it, I decided to lock the GPU at 875 MHz, again just below the 900 MHz maximum, to make sure that no dynamic clocking was going on whatsoever. I just really wanted a nice, stable GPU, and dynamic clocking doesn't seem to help with stability.

In order to lock the frequencies, I would need to hack the card's BIOS to eliminate the low-power modes. I accomplished this, with some frustration, with a set of tools specifically designed for ATI cards. You can find them here:

1. ATI Winflash [link]
2. ATI Flash [link]
3. Radeon Bios Editor [link]

The steps are pretty simple really, but must be followed very carefully. It's also critical that you have a second working video card in case something goes wrong. I, for one, bricked the card with a bad BIOS update using Winflash, and had to swap in a 9600GT with the 5850 in the secondary slot to re-flash with ATI Flash. Luckily, these things are pretty resilient, and the process worked just fine.

So, first unzip all of the above files to their respective folders. Then open up the Radeon Bios Editor. Click on "Acquire/flash..." down at the bottom to open up the Winflash dialog box. Click the "Browse..." button and find your ATIWinflash.exe that you downloaded. It should find your card and enable the "Acquire BIOS" button. Go ahead and hit that. This will bring the BIOS settings into the application.

I recommend skipping all of the settings except for the "Clock Settings" section. In here, I set the "GPU (MHz)" and "RAM (MHz)" all to 875 and 1250 respectively. I also selected "---" from the voltage drop down for each of the 7 Clock info sections to ensure that the card stayed at full power 24/7. While this might be achievable with the "Powerplay states structure" section, I wanted to be sure. UPDATE: Here's a screenshot of what mine looked like, click for full size:

Once you have those values changed, save the BIOS out to something like "New5850.rom" and prepare to flash.

For this part, we'll need to get into a DOS prompt to avoid potentially bricking your card like I did. If your PC still has a floppy, this will be pretty simple, but if not, you'll need to create a USB or CD boot device. There is an excellent write-up on how to do this, right here, so I'll forward you to that to make your USB booter. I do recommend skipping the final part where you copy all of the files over, as we really just need the system files on this drive. I actually had to remove the autoexec.bat and config.sys on mine to get it to boot at all.

Once your USB drive is bootable and ready to go, create a folder in there called "ATI" and copy the atiflash.exe file that you downloaded above over to it. Also throw your New5850.rom file in there. Then it's time to reboot and enter DOS. I tapped "F8" for my Asus motherboard to pull up the boot device selection list, then hit the Corsair device to get in.

You'll be greeted with a very familiar prompt for those of us who were computing in the days before Windows, but since I know that some of you weren't with us back then, I'll write out the commands you need here. Just type them in exactly as you see them, hitting enter at the end of each line, and you should be greeted with a "Reboot system to complete flashing" prompt at the end.

• cd ati
• atiflash -unlockrom 0
• atiflash -p 0 new5850.rom

The unlocking is particular to the Asus cards, but should work like a champ. Of course this assumes that you put your atiflash.exe in a folder called "ATI", that your new BIOS is called "New5850.rom" and that you have only a single Radeon card in your system.

Viola! Upon the reboot, you should have a card that stays on all the time. I've noticed that my idle temperatures are much higher than they were, no doubt because I removed all power saving features from the card, but I see no more flickers, ever. I did notice one serious bug, which is that if I attempt to enable ATI Overdrive, the secondary screen went gray while the primary screen turned blue with vertical stripes, and the system became unresponsive, however overclocking with MSI Afterburner still seems okay.

I'll still testing the display standby issue to see if this resolved that one too, and I'll be sure to let you know if that is also fixed.

So, there you have a very nasty fix to a very simple issue, albeit a very risky and unrecommended resolution.