I just got my gigabyte r9 270x 4GB card today and when I try to run it with cgminer is hashes at 20kh/s which I know is not right this should be upwards of  400 kh/s atleast im new to all this I also have a gigabyte hd7770oc which hashes just fine at ~200kh/s please tell me what im doing wrong ive been messing with this for about an hour and a half and am just about ready to give up! I even tried to use the settings I found on the litecoin mining hardware wiki for the gigabyte r9 270x 2GB but when I do that I get a 61 error.

windows 7 x64
cgminer 3.7.2


this is my .bat d-0 is the new card

start cgminer.exe --scrypt -d 0 -o stratum+tcp://yum.bettercoin.org:3333 -u user.1 p x
start cgminer.exe --scrypt -d 1 -I 17 -g 1 -w 256 --thread-concurrency 8000 -o stratum+tcp://yum.bettercoin.org:3333 -u user.2 p x



Even if I disable the HD7770oc in the device manager it still doesn't want to work right.

I'm looking to buy a new video card I'm interested in 2 of them they are the same identical cards except one is 4gb and the other is 2gb the only other difference is price the 4gb is $50 more .... I guess what I'm asking is the extra 2gb worth $50 when it comes to mining?  It's gigabyte r9 x270 they make a 4gb and a 2gb .