If its for mining alt coins I think its better to choose 4gb. Don't just see 50 $
Well I ended up buying it because I got $20 off and I will mostly be mining altcoins considering I will probably only be around 700 kh/s I have a gigabyte hd7770 and now a gigabyte r9 270x I'm getting 200 kh/s from the 7770 I assume I should get around another 500kh/s from the x270 .
As i have read some thread in other forum sometime Different GPU's dont work together so are you sure you can run 7770 and 270 together?
Im running a 280x an two 7790 , and its running fine. You just have to run each card in a seperate cgminer instance.
My *.bat looks like that:
start cgminer.exe -d 0 --scrypt -I 17 -g 1 -w 256 --thread-concurrency 8000 -o stratum+tcp://pool1.us.multipool.us:3358 -u user.1 -p x
start cgminer.exe -d 2 --scrypt -I 13 -g 2 -w 256 --thread-concurrency 8196 -o stratum+tcp://pool1.us.multipool.us:3358 -u user.2 -p x
start cgminer.exe -d 1 --scrypt -I 17 -g 1 -w 256 --thread-concurrency 8000 -o stratum+tcp://pool1.us.multipool.us:3358 -u user.3 -p x
The advantage is you are able to set optimal settings for each card. If I run all cards in one cgminer instance, i just have 800kH . With 3 instances i get 1200kH.