I'm sure I could use just the R9, but I was hoping I could just swap out the 6770 for the R9.
First I was using the 4250 by itself. Then I upgraded to the 6770 (and stopped using the 4250). Then I learned of SoftTH which is easy to use/configure and allows me to span games across multiple monitors at very high resolutions using multiple gpus (so I started using the 4250 + 6770).
I bought the R9 270 as an upgrade to the HIS 6770.
I wanted to change my setup as little as possible while getting better performance (I'm a casual gamer and don't really like spending time messing with my computer hardware).
I'm not familiar with using a single gpu to drive multiple screens for gaming (I think AMD calls it 'eye affinity' or something similar). I'm lazy and didn't want to have to research this (and SoftTH was already working for me). I'm also cheap and not a heavy gamer so I wanted to minimize what I had to buy for the upgrade. I was hoping the card by itself was enough.
I don't think SoftTH works with a single GPU and I don't know how the performance of the R9 driving 3 monitors using eye affinity (or whatever it's called) compares to SoftTH+4250+R9 driving 3 monitors (assuming I could get it to work).
I thought SoftTH+4250+6770 was awsome (and the setup was cheap since I already had the hardware).
Now (assuming I have to use the R9 alone) I need to buy new cables and possibly a new monitor if I want to use three displays:
2 of my monitors (called A & B) have VGA connections only while my 3rd(C) has VGA + dvi-d.
So I can connect 'A' to the card's DVI-I, 'C' to the card's DVI-D, and either buy a new monitor (to connect to the card's DP output) or buy a DP to analog adaptor (which I understand is not cheap) so I can use my 'B' monitor.
I should have researched the card more before I bought it. I think if I had bought an nvidia card I wouldn't have the driver issue so I could use the 4250 with the nvida card and might have only had to buy an inexpensive cable or two.
Sorry for the long message and thanks for replying to my original message,