According to 3DCenter.org, dual-gpu GK104 is expected between 14th to 17th May. NVIDIA is planning their GeForce GTX 690 just after AMD releases their dual-chip Radeon HD 7990, which is most likely to come in late March.
NVIDIA was disapointed with AMD Radeon 7000 series performance. They were waiting for AMD’s three most important Radeon segments, which are high-end, performance and mid-range cards. Since AMD has just released their Radeon 7800 series, NVIDIA has full lineup of most important cards from its main opponent.
3DCenter focuses on new Kepler design, suggesting that GeForce GTX 690 would be much more powerful than GTX 590. GeForce GTX 590 was only 40% faster than GTX 580. Site predicts that GTX 690 may be 65-75% faster than GTX 680. Rather than that Radeon HD 7990 may also be much better dual-gpu solution than its predecessor. Therefore, it may be hard to choose between these two cards, since they may offer similar performance.
|GeForce GTX 690 (2xGK104)||3072||256||64||2 x 256-bit||~330W||525%|
|Radeon HD 7990 (2xTahiti XT)||4096||256||64||2 x 384-bit||~300W||520%|
|GeForce GTX 685 (GK110)||2304||192||48||384-bit||~250W||420%|
|Radeon HD 7970 (Tahiti XT)||2048||128||32||384-bit||~200W||330%|
|GeForce GTX 680 (GK104)||1536||128||32||256-bit||~190W||310%|
|GeForce GTX 670 (GK104)||~1280||128||32||256-bit||~160W||300%|
|Radeon HD 7950 (Tahiti Pro)||1792||112||32||384-bit||~155W||290%|
- READ MORE (Source): nVidia Kepler DualChip-Lösung auf GK104-Basis im Mai | 3DCenter.org