yeskay :
I too have read, those specs. Check this -
AMD Radeon R7 240 2GB
AMD Radeon HD 7570. Now whom do you believe?
The fact is 7570 GDDR5 card has a far better memory bandwidth that can handle double the amount of data than the R7 240 GDDR3. Anyway both are very low profile entry level cards and why you chose these? You've a budget in your mind? I'll get you a better one.
It's difficult to know what to believe. Looking at the specs you'd think the 7570 would perform better, but perhaps it's the superior clock speed, actual shader performance, and/or pixel rate which makes the R7 240 significantly outperform the 7570 in 3D Mark? It seems that the 7570's GPU would have to be hindered in some way in comparison to the 240 for it to score so much lower.
I read somewhere that the 7570 isn't officially supported by the latest drivers from ATI/AMD. I wonder if its the quality of the drivers that would make 3D Mark score the R7 240 as 2x as fast?
The reason I'm looking at these 2 cards is because they're (potentially) the best price per performance under $30 that I have found, but I'm finding almost no actual gaming benchmarks for the 7570 1GB DDR5 that can be compared to the R7 240 2GB DDR3.