Can't OC xfx 5850 until i flash new bios?

No, you can still overclock it. You just cant overclock it very far. It is best to flash the card to asus bios.

THe card is fairly simple to flash and only takes about 10 min if you klnow what you are doing (1/2 hr for those who dont).

Here is the asus bios:
http://www.techpowerup.com/vgabios/58225/Asus.HD5850.1024.090925.html

And here are some instructions on flashing a cards bios:
http://www.mvktech.net/content/view/17/37/

 
Solution
I would overclock from the ATI software first... yes, that limits your OC potential, but that might be as high as you want to go. If you're still keeping your temps in check and aren't getting any artifacts, then and only then would I consider flashing the card.
 


Well, the Asus bios is unlocked and has a better overclocking potential. Also, correct me if im wrong, but i believe there are voltage limitations on other bios's.
 
i dont know if its the same with the 5850, but with my 5870 i was able to overvolt and reach 1000mhz WITHOUT flashing the BIOS. simply DL MSI afterburner, and enable unlocked overclocking in the .cfg file.

try it at least, it may save you the effort of flashing the BIOS
 
I had my 2 5850's for one week and flashed them to an MSI 5870 BIOS (they were not MSI cards). The reason for doing that is the 5870 bios ups the GPU voltage and keeps Powerplay intact - throttling down when not in 3d mode. It runs fine at 875/1200, I have had them to 900/1200 but the 5850 is not as capable of dealing with the voltage and heat as the 5870 card. Heatsink is smaller and not as many VRM's.

I personally dont like the MSI tool as it locks the increased voltage and speed in place in 2d and 3d mode and never throttles back. Im not saying anything bad about it, I just like my system to run quieter when doing desktop work.

Technically my warranty is void. If the cards catastrophically fail some day they wont be able to read the bios either. If they dont catastrophically fail then I will attempt the reflash back to spec. If they reject my claim (someday) then I will buy new cards.. Over clocking is about taking chances...

 
@vv

yeah, its for that reason that i only overvolt when i benchmark. until we get an updated catalyst suite, i don't want to keep my 5870 at 1000mhz.
but flashing the bios seems like a lot of trouble, when ATI will be raising the maximum clocks in CCC long before the 5870 NEEDS to be OCd.
 
The only reason I don't think I can use the CCC for OC'ing is even if I change any of the speeds by like 5 mhz (even downgrading from 725/1000) when i run my mouse along my taskbar and do the aero preview thing, you start seeing black lines flashing a bit. I haven't tried it in game yet, but I assume that if I already see problems with windows, there would also be problems in games. Has anyone else run into this problem?