Sit down before you read this one, we will wait for a second while you do. OK, now, where to begin other than the obvious, TSMC shut down 28nm production about three weeks ago.

No, we are not joking, word has reached SemiAccurate that TSMC halted 100% of 28nm production in mid-February to make unnamed changes to the process. Since only Nvidia was having issues, and those are not really process related, we have no explanation as to why they would take this drastic step, but yields don’t seem to be it. That said, we are quite certain that it happened, and is still in effect.

Sources tell SemiAccurate that the stoppage was quite sudden, and production should resume in short order. One source said that by the end of March, volumes would be back to where they were before if not a lot better. Checks with the channel have confirmed an abrupt stop in 28nm chip shipments, not that there were many to begin with. TSMC is privately promising a quick and planned down time with a resumption in production very soon.

Whether wafers in process were continued, paused, or scrapped is not known. If the parts that were started can be continued on once the switches are flipped back to ‘go’, the production blip won’t be that bad. Because all are saying the whole episode will be but a bad memory by month’s end, we believe that wafers were just paused. If that were not the case, if production restarted today, you would not be seeing new chips coming out until June.

Checks with various points in the chain for graphics cards show that there was actually a large amount of supply of 28nm AMD parts in the channel from chips to cards. That supply, while not infinite, should be enough to keep products on the shelves until new parts come back out. Basically channel inventory will be depleted about the time it starts being replenished. Best case, buyers won’t see any problems, worst case, 1-2 weeks of short supply. AIBs however have to sit on their thumbs and do nothing until the new parts come in, then it is overtime shifts until demand is sated.

Things get much more complex for Qualcomm. 28nm Kraits are not shipping to end users, and as far as we have heard, nothing has been given a definitive ship date. If there is a 2-3 week delay, the OEMs and carriers will be peeved, but the end user will have no clue about any problem. It is internal, logistical, and annoying, but not a PR disaster.

Nvidia on the other hand is announcing their newest family of parts next Monday. It is a good part, but supply is the proverbial elephant in the room. Ivy Bridge is launching soon, and if GPUs aren’t ready, things get ugly in a hurry. Given Nvidia’s uncharacteristic whining during the last conference call, you now understand what they were prepping the analyst community for. SemiAccurate still believes that Nvidia is the only company seeing 28nm ‘yield problems’ and the real problem has it’s roots in Santa Clara.

All in all, this is nothing more than a horrific failure. Complete 28nm stoppage at TSMC with no public word, no explanation, and no known concrete resumption date. Sources tell us that it is indeed temporary, but until there is a good explanation, don’t assume anything.S|A