One of things that we discovered two weeks ago was why AMD is having an up and down relationship with GlobalFoundries, which is successfully negotiating its way out of the "no pay-no machines" minefield which was left for them by the former AMD management, most notably Hector Jesus Ruiz and Mr. Bob Rivet.

With the GlobalFoundries fully equipping all of its five clean rooms on Dresden site into one highly-integrated clean-room facility (the "copy right" strategy, cornerstone of APM), the factory can output a lot of wafers if all things are kept in check.

For quite some time, we suspected that one of key reasons for AMD?s shift to a contract with GlobalFoundries (to pay for fully functional silicon dies only)  was due to the teething issues with the first new CPU architecture from AMD in eight years (first one since April 22, 2003 when the company launched K8), the mythical Bulldozer.

However, we have managed to confirm from multiple sources that we were wrong with the Bulldozer guesstimation and that the real culprit for AMD?s switch might be the fact that Llano APU yields are nowhere near where they should be. According from the sources familiar with the matter, the CPU side of this revolutionary 32nm SOI silicon is doing quite well, but there are a lot of headaches with the GPU part of it. This results in lower-than-expected yield and the shortage on the market ? as AMD?s TSMC-manufactured APUs turned out to be a big hit, and the initial reviews of GlobalFoundries-made Llano were nothing else but remarkable (you can read our own review of AMD Fusion A8-3850 "Llano" APU here).

After all, this is the first GPU manufactured using Silicon-On-Insulator technology, since all previous GPUs from just about any company that ever did graphic chips and GPUs ? were  manufactured using bulk process at one of foundries such as TSMC. By shifting the GPU design from bulk to SOI, AMD and GlobalFoundries encountered a lot of issues, since Dresden facility relies on custom transistor libraries which were long before the pride and joy of AMD, now GlobalFoundries. Getting the Llano GPU part to seamlessly integrate onto the more than dozen generations of improved custom transistors at Dresden is a major task, and GlobalFoundries is still working on it.

In a nutshell, if you see a shortage of Llano parts, it?s not because there is a big bad wolf out there, but it is due to lower-than-expected percentage of fully functional chips from one side, and bigger-than-expected demand from the other.

Things should work themselves out by 2012, when AMD is going to launch Trinity, the Bulldozer-powered APU.