Lets assume that the chip taped out on work week 28, more or less July
15. TSMC runs 6-8 weeks for a ‘hot lot’, but our moles say currently it
is much closer to 8 than 6. Add in just over 2 weeks for initial card
build, bring-up, testing, debug, and making any fixes. Lets just call
it 10 weeks, October 1 or so.
From there, if everything were to go 100% perfectly, you could expect another 10-12 weeks for mass production to begin and the first cards to be shipped back to the board partners. So, if something magical happens, NVIDIA COULD have a DX11 GPU ready before the end of the year. Now, the author of the piece linked above seriously doubts that will happen, but we’ll wait and see.

NVIDIA has done GDDR5, 40nm GPUs before: Comparison between the die sizes on the 40nm mobility GF 200M GPUs – estimates only
From those reports the GT300 is going to be a pretty big chip:
Back to the chip itself. Our moles say it is 23mm * 23mm, or about 530mm^2, and considering they told us that GT200 was 24*24 months before it came out, we will take their word for it. This puts GT300 almost dead on even between GT200 on 65nm and GT200 on 55nm. If you recall all those charts about alleged GT300 sizes and specs floating months ago, we will say the same thing we said then, complete fabrications.
And keep in mind that this is built on a 40nm process, not a 65nm or 55nm like previous generation GPUs. This adds to complications of course since TSMC has been known to have 40nm production problems from day 1.
Finally, in another piece over at Semiaccurate, they are reporting that there are going to be five total GPUs based on the GT300 architecture at or near launch time, whenever that is. That is interesting because as of today, NVIDIA STILL doesn’t have 5 different iterations of GT200 in the market.
Yes, the oft-delayed monster is going to have children, four of them. For the sharp-eyed, this is more than Nvidia has done at any time in the past. While none of them have taped out yet, our moles say that Nvidia usually waits until they get the first silicon back to see if there are any changes that need to be made to subsequent designs. With mask sets running into the 7 figures, this is what you call a smart move.
So there you go: the GPU market is heating up just in time for Windows 7 to hit the shelves and enthusiasts to once again get excited about PC gaming!