Both are very awesome cards that cost the same amount of money. However that being said both are different as well. The Titan will be used in very high resolutions in excess of the 4-5k range while most normal pc gamers use anything from 1920x1080 to 2560x1600.
Now with the Titan you have to keep in mind that it is a single GPU card and as time goes on you can easily add to it. Right now it is keeping up with the 690 and beating it on some occasions. Now as for the 690 it is a dual GPU card so take all those stats and cut them in half. if you want to make it single GPU vs single GPU also because the 690 in itself is a slightly underclocked 680. The only thing different is that there are 2 of them on 1 PCB giving off the illusion that it is a single gpu and that gives alot of people the wrong idea.
The fact boils down to that of we now have a relatively up to date dual GPU card being beat on some test by a single gpu card is amazing and makes me sad at the same time lol. I am an owner of the 690 myself and was hoping it would of lasted a little longer but I am sure the 790 will be amazing and I will own that too. Now if you want my opionin I would say go buy the titan and as the price drops on it over time add to it.
| CPU: Intel: 3770k |
| Ram: 32GB Corsair |
| PSU: OCZ ZX 850W |
| HDD: WD Black 2TB |
| GPU: EVGA 690 GTX |
| SSD: Samsung 840 Pro 512GB |
| Case: Cooler Master Cosmos II |
| Motherboard: Asrock Z77 OC Formula |
| Pictures of Rig:
http://imgur.com/a/Dx1pA#24 |