I have a major question.  
 
I have bought an HIS 2600 XT 512MB Core clock: 830MHz Memory Clock: 1920MHz *GDDR 3* MEMORY {http://www.newegg.com/Product/Product.aspx?Item=N82E16814161174}
...however...I am wanting to buy the  
 
MSI 2600XT Radeon HD 2600XT 512MB 128-bit GDDR4 Core clock: 850MHz Memory Clock: 2300MHz for a crossfire set up! {http://www.newegg.com/Product/Product.aspx?Item=N82E16814127303}
 
Now there is a big problem here because of the clock differences...The good ol' catalyst will cut the power of the better card to "make it compatible" with the lower card, thus CROSSFIRE...however....I don't want this. I want to flash the bios of the HIS card to match the MSI cards specs, etc so the computer thinks that there are two of the same**BETTER, FASTER** cards...THUS no power/performance cuts to the better card...Is it possible ***(AND SAFE)*** to flash the HIS card to the specs/power of the "better" MSI card?
 
THANKS EVERYONE!
 
Drew

You can try out the newly sticked guide here by randomizer: http://www.tomshardware.com/forum/ [...] g-flashing

I was hoping someone could give me information IF it's okay to flash over my "lesser" card to make it LOOK like the newer, better, ATI card...because I do not want my better card to be downgraded in crossfire...can anyone tell me if it's okay to flash my DDR3 with the DDR4 bios? even though the core clk and mem clk are higher? I was hoping for advice on if this will work or not? That guide seems to be more of a "how to" vs...is it "safe" to force the bios of my HIS card to the bios of the MSI card question I was curious about...

I'm sure you can OC the His 2600XT to 850MHz without any issues, but probably not the memory. Use the vidcard OCing guide here to OC the HIS 2600XT memory clock and see how high you can safely go.

You better mod your old card current bios with new clock settings. The tool to mod ATI bioses is either CBABE from ComputerBase website http://www.tomshardware.com/review [...] 916-9.html or the link evilonigiri linked to.

SO basically...The new MSI card with the Mem clk speed of 2300mhz is going to have to slow down for my HIS card no matter what? If I can't get my mem clk up to 2300 (starting from 1920mhz on the HIS) then the MSI is going to have to slow in crossfire mode? correct? (in regards to mem clks only not core clk)

Pretty much. 2300MHz is rather hard and unsafe to do for DDR3.

Ok...thanks a ton for the help...I guess I'll just focus on getting it as high as possible to eliminate the better card from going down in specs...
 
THANKS!

No problem. I also would like to add that 2000Mhz vs. 2300MHz has little difference in fps.