5870 and 6970 are architecturally different. 5870 is VLIW5 (5 stream processors programmed in a single word) and has 1600 stream processors (SPs). 6970 uses the simpler VLIW4 architecture to improve SPs utilisation for mainstream gaming and has only 1536 SPs. The simpler architecture makes 6970 faster than 5870 on gaming tests. But Bitcoin mining is a completely different story. It is highly parallel and can max out the VLIW5 of 5870 thus making it faster than 6970 on equal clock speeds. 5870 is also more power efficient since it contains less transistors than 6970.
Your first post? What an amazing first post to the forums! Sure beats the "Bitcoin is doomed since you guys never thought of people copying their wallets to 2 computers" variety.
Not to get off topic but is that possible? And A follow up question i guess is did they think they could double spend if they did that or something? Becuase that just sounds rediculas.
To the OP, i would have checked the hardware comparisan chart before buying but too late now. Im thinking about just getting another 5670 so i can have them both run my games abd mining faster. Cant wait til the high end cards start to lower in price.