IT LOOKS LIKE the GPU roadmaps are being torn up and plan B's are coming out of the woodwork left and right. The current problem? TSMC's 28nm process, or lack thereof.
When we first told you about ATI's Northern Islands, (here, way at the bottom) the plan was simple - a new architecture on next generation 28nm HKMG processes, coming out in the next new year, 2011. The lead off parts were due to come on TSMC's 28nm process, which is set for Q1/2011, followed by derivatives on GlobalFoundries' 28nm process. Since that was due about a quarter after TSMC, the first out of the gate was going to be TSMC.
The problem is that from SemiAccurate's unscientific poll of asking several involved companies, no one seems to have any confidence that TSMC will deliver 28nm HKMG on time. Many expressed skepticism that it will deliver at all, but let's give it the benefit of the doubt here.
If you recall, TSMC 40nm was set to come out in Q4 of 2008, and it wasn't working until Q4 of 2009, more or less. Problems still plague some users though. We broke the news that TSMC canceled it's 32nm node completely, something the company has never done before.
Northern Islands(NI) from ATI and the next generation of Nvidia parts were slated to use the 32nm process, and several ATI slides have leaked showing that explicitly. When 32nm was pulled, the decision initially was made to move NI to 28nm, delaying it by a quarter or two. Fair enough.
Meanwhile, TSMC threw out its 28nm process and replaced it with a completely different one. TSMC initially claimed to use a technique called 'gate first', and that was slipping by quarters at a time. One day, it announced that it threw 'gate first' out the window and replaced it with 'gate last', a completely different process. On top of this, it pulled the roadmap in a quarter.
To call companies skeptical of the new roadmap is being overly kind. No one believed it, but what can they do? Easy, put plan C into place, and for ATI, that is called Southern Islands.
Southern Islands (SI) is a 40nm family, and from early information, it looks to be a hybrid between Evergreen and Northern Islands. The architectural details are quite slim now, but it looks like ATI took the uncore from NI and put the shaders from Evergreen on it. Think of it as taking the parts that were done and available, and putting them together.
Because it is the only option at this point, SI will be built on TSMC's 40nm process. This is good because it is known, and ready, pulling in the timetables. Low risk means low chance of problems and quick time to market. Expect SI sometime this fall. Rumors abound that some family members have already taped out, but that is far from confirmed.
In any case, ATI will likely have a fully refreshed lineup before Nvidia has its Fermi GF100 GTX4xx line fully out the door. It looks like this fall's GPU battle will be more of a howitzer versus pen knife match rather than a duel.
