Better change ur graphics card if u want to mine.
The investment u make is worth more than u can think.
Mind me asking what you're earning at the moment with your 6870? I am tempted to buy a better GPU. Hard to know if it's worth the investment if difficulty is going to keep climbing (unpredictably as well.)
For the past 4 days mining i got around 19btc, on average 4btc daily, running 23/7
The difficulty changes are not unpredictable. You can look at the estimate here or calculate it yourself. Every 2016 blocks, the network (all of the clients) recalculate the difficulty such that over the past 2016 blocks, using the new difficulty would result in around 10 blocks being found per minute.
True but I was thinking of the longer term... e.g. where will difficulty be in 2 months? This seems harder to estimate, as it depends on unforeseeable events, like bitcoin getting a sudden burst of publicity.
For long term, the next difficulty will be <=70000 , & then after 2 months it will be 23000909.
In 2 months not a single 5970 is enough to mine, u need atleast 2-3X 5970 to mine.
U better instead of mining try buying & selling, that will be easy & profitable.
