if you didn't already have a 670, then yes.
but in your case you already have a 670, so it will not be worth the money for the upgrade.
if you really
are thinking about spending more money on graphics horsepower, then in your case i would go for an extra 670 in SLI sense you already have a 670. 2x 670 will blow away a single 770.
so rather have 2x 670 than a single 770 and a 670 just laying around. you might aswell use the card you have just bought.
---------- Post added at 10:55 AM ---------- Previous post was at 10:53 AM ----------
Originally Posted by starrrie
Sorry for asking a no brainer... What I meant was should I get sli or just one 780/770 which will be better ?
i hope the answer above explains it when taking the 770 into a count.
for the 780. well... again, it's gonna cost you, and it's not like you are gonna get your money back from the 670 you just bought.