Rog Matrix is the fastest single GPU on earth afaik, but for a price... GTX 690 is a dual GPU beast with very good efficiency, if you are willing to pay the price. If you ask about performance, it is the GTX for sure though i'd try to avoid dual GPU cards as much as possible because of the possible performance issues/bugs that may occur in some games/drivers
It's not a fair match the 690 is basically two reference 680 so of course it beats up a single 7970 even such as the Asus Rog Matrix Hd 7970.I honestly cannot recommend a 690 for the price it's not worth it.I would go for gtx 670 or Asus Rog Matrix Hd 7970
asus rog matrix is not worth the extra price. not worth the extra heat it produces not worth it for its too huge to fit in most cases not worth it for the many extra features it offers that many wont even use.
so sapphire 7970 ghz is the better buy
Yeah honestly i don't think any those cards are worth the price lol! I would recommend Sapphire's HD 7950 Vapor-X comes with a large dual-fan cooler that uses the company's famous vapor-chamber technology. On the Vapor-X you will also find a "Lethal Boost" button which switches to a second BIOS with higher clock speeds. With this BIOS, clocks are increased to 950 MHz GPU and 1250 MHz memory.
Pricing of the Sapphire HD 7950 Vapor-X is $330 which is a 10% premium. Also,MSI's GTX 670 Power Edition uses the famous Twin Frozr IV cooler from the MSI Lightning and comes with a large clock speed boost out of the box, making its default clock speed even higher than GTX 680 stock clocks.That would be a solid choice for the price imo they currently are going for $359.99 a piece that doesn't look unreasonable, given the improved cooling and higher clocks but it's up to you.
There was a review that I remember watching for the matrix card and it didn't get so hot of reviews. I also agree that spending money on the either would be rather overkill at the moment. Also in a thread I was posting in people were saying that the 690 only supplies 2 gigabytes of actual usable ram which is shady if that is true. If money isn't a option 680/7970 ghz edition, if you are after more of a value 670, standard 7970