4xxx Radeon's can mine just fine, but it's not economically feasible at this time (high power consumption, low hash rate)
That is also wrong. I have a 4870 as the OP, and standard I got ~82 MH/s with poclbm -w 256 -f 60.
Since I'm also using the computer normally while mining, the only real cost is that of idle vs full load, which is 80w at stock speeds.
By overclocking core and underclocking memory to 830/190 I get to 94.5 MH/s, giving an 85w effective draw during mining, but overall 30w lower due to memory underclock.
So it is most definitely profitable.
4870 is 150W at stock, which is why I stopped mining on mine, as I was paying more for electricity than I was getting back from BTC. Not sure if it's profitable now BTC value have gone up, as the difficulty has also gone up.
For me it's quite profitable.
The energy price here is $0.233 per kw/h. Seeing as I use my computer normally during mining, I'm only interested in the difference between idle and load, which is 80w on stock.
Overclokcing core and underclocking memory yields a 5w increase in difference between idle and load, but a 30w decrease in total usage. This gives me an effective cost of 55w for mining.
At $0.233 per kw/h that equates to $0.308 each day. 1BTC is currently at $16.33 on mtgox, and at 94.5 I would get roughly .02 BTC a day on deepbits PPS model.
So each day I get about $3.27 worth of bitcoins.
Now if it would have been a dedicated mining rig, the total power draw is 210w, giving a daily energy cost of $1.17, which is still profitable at current prices.
Can you help me set get this set up since we have the same GPU??
yes I have already looked at the beginners guide, but I am not tech savvy enough to figure out how to set up all the command line stuff.
Writing it up, give me a sec.