Well, trying to beat a gtx 690 is a rather bad reason to justify the delay, business is the priority, selling the product brings in revenue
In the high end market holding the performance crown is everything and means you can charge a premium. Just look at what happened with the 7970 when GTX 680 launched. Nvidia pretty much pushed the 680 as far as they safely could to make sure it would be faster than then 7970 by a decent margin and can now charge more for it than they should by logic. GTX 680 is essentially a mid range card looking at die size and the card itself and should sit somewhere around/just below the 7950 in terms of pricing (6950 vs 560 TI is a similar situation looking just at the physical cards)
Had AMD known about the performance level of 680 they could possibly have been able to launch the 7970 at 1000-1100 core since the headroom is huge atm with the stock at 925. Had they done this they could have stuck to their price premium for a much longer period since 680 vs 7970 performance hadn't been as clear as it is now, and there wont anything else coming from Nvidia except GTX 690 in the near future afaik.
That's why it would make sense to wait with launching the card, another thing is that the higher they plan to push the card to beat the "expected" 690 performance, the more aggressive they have to be with binning the 79xx cores and it takes longer to build up enough supply for a hard launch.
In this market you either have the performance crown and you get paid for having the "best" card or you sell the second best card in the world cause it has good performance/price, guess where they would rather sell their cards.
Yes. The 7970 launched in early January, the only 28nm product on the market, new technology, AMD took advantage of this position, and set a desired price. nVidia countered with their 680 in March, in order to attract sales; there should be reason why a customer would pick nVidia's product over AMD's (market has brand fans and non-brand fans): releasing a product superior to a 7970 is no doubt the focus, despite being a little over two months late after the 7970's launch. nVidia launches their 680, sales decline for AMD's 7970 (though the entire single gpu lineup is already being sold in the market from AMD, nVidia only has its most expensive single gpu card out), so AMD re-prices its products to be more competitive against a now present competitor in the 28nm market.
Graphics card do improve in performance from one generation to another, I would be tempted to say at least by 30% (not set in stone), just to throw a number out there for reference. Early launches do pose a risk, the possibility that the competition will tweak/reconsider product specs and later down the road release a superior product (better than 30% improvement, into a competitor saturated market). I am guessing this what you are referring to? I am not an electrical engineer (though I do know a few), but I know clock settings on a chip are specified by a number of factors in its design, my initial reaction in the 7970 being able to operate from a stock 925 to a 1250 MHz range told me they wanted to have headroom that can compete performance-wise with a later released nVidia product.
nVidia intends to release their 690 sooner than anticipated according to their road map (originally Q3?), an interesting marketing strategy. Indicating they want to release all high-end/enthusiast cards first (then mid/lower end later), in order to capture back more of the high end-market (expen$ive) that they been shut out from since January (7970). Had the 7990 been released in March (just before or after 680 release), then nVidia would most likely be under more pressure in attempting to establish itself in sales/market share of this generation of GPUs (
again brand fans are the loyal buyers, expanding by luring non-brand fans is important in the market). Long story short, we have a delay for the 7990, something fishy is happening...
(it is difficult to slap two Tahiti cores onto a pcb)A new Tesla Kepler is being released on May 14, double the transistor count than gtx 680, nVidia's first move for this generation of high performance computing?