Everyone keeps saying that the 7870 and 270X are basically the same. While hardware wise, this is mostly true, there are a couple of important differences you should note.
#1, better GDDR5 RAM in a 270X. It goes from 1200MHz (4.8GHz effective clock rate) which has a memory bandwidth of 153,600MB/sec in a 7870 to the 270X version which has a 1400MHz memory clock (5.6GHz effective clock rate) which has a memory bandwidth of 179,200MB/sec. That extra 25,600MB/sec the 270X gives you will do a LOT for your gaming, period. Since the mining is memory intensive, it is really going to improve that dramatically as well.
I've been researching all the cards from AMD this last week, and have set up a card comparison in an excel spreadsheet, which includes the cost I can get the card from Newegg.com. Right now, I can get a PowerColor R9 270X for $189.99US with free shipping, or a HD 7870 for $149.99+$6.05 shipping. Using formulas to calculate the performance of the cards, taking into account power consumption of each card and what my cost/KW hour is in my area of the US, I have calculated the first year cost of ownership (including purchase price), and have yielded a Performance/$ ratio. Using that Performance/$ ratio, the 7870 came out on top, barely. I mean
barely. However, when I include how much extra $ per year I can earn with the 270X over the 7870 by mining, the 270X comes out ahead for the first year, again, barely.
Bottom line, close call. In the long run, the 270X will more than pay for itself if you make wise use of it, faster than the 7870 will. Also, the 270X will handle newer DirectX titles and newer OpenGL titles without sacrificing features those titles bring in. For that reason, and that reason alone, I have decided on the 270X, since all other things are pretty much equal. You see, I don't want to spend money upgrading to a DirectX 11.2 card later.
270X prices have begun to drop. I have also decided to wait a couple more months to monitor the price drop to try to get it at the best time. Because of the market saturation with the mining, the mining has become less profitable per card, and this makes the price of the 270X less attractive to miners. As more people get into the mining, the card price will continue to drop. Expect a good drop comparable to the 7870 within the next several months. My opinion from the exhaustive research I have done this week. May not be worth anything, but there you have it. Exhaustive in this case doesn't mean necessarily complete, but in my case "lack of sleep due to staying up too long researching it." If you want to be sure, do your own research on it.
But it will be better than my HD5750 I got on a steal of a deal lol
