[Galaxy S 4 General] BarryH_GEG:
Here's a question. Why did Samsung go to the trouble of even creating a second version of the SGS4 with Octa? There are no supply constraints on S-600 so they could have selected it exclusively from when the SGS4 was in the design stage. It's a lot more costly and cumbersome to produce and manage two different h/w and s/w configurations. S-600 could have easily been used with a HSPA radio; HTC's doing it with the One. And Samsung Electronics isn't bound in any way to use Samsung Semiconductor parts as seen by the Intel chip showing up in the G-Tab 3. And since Samsung Electronics drives most of Samsung Corporate's profits I highly doubt they were strong-armed in to favoring Samsung Semiconductor over Qualcomm; even for 1/3 of the SGS4's produced.

Here are my random thoughts.

Current LTE basebands support a maximum of six bands. There are 40 in use. The liability of coding interfaces between Octa and multiple iterations of market-specific LTE basebands was such a burden that it made using S-600 which already has compatible s/w to work with any of Qualcomm's basebands the better solution.

SAN DIEGO – February 21, 2013 – Qualcomm Incorporated (NASDAQ: QCOM) today announced that its wholly-owned subsidiary, Qualcomm Technologies, Inc., introduced the Qualcomm RF360 Front End Solution, a comprehensive, system-level solution that addresses cellular radio frequency band fragmentation and enables for the first time a single, global 4G LTE design for mobile devices. Band fragmentation is the biggest obstacle to designing today’s global LTE devices, with 40 cellular radio bands worldwide. The Qualcomm RF front end solution comprises a family of chips designed to mitigate this problem while improving RF performance and helping OEMs more easily develop multiband, multimode mobile devices supporting all seven cellular modes, including LTE-FDD, LTE-TDD, WCDMA, EV-DO, CDMA 1x, TD-SCDMA and GSM/EDGE.

Being the first commercial implementation of big.LITTLE, it made sense to get it out in large (but not too large) quantities to gain experience with it in real-world l use and further tune and tailor it. If Samsung Electronics thought that Octa wasn’t ready there’s no way in hell they would have launched it in a “flagship” phone under the scrutinous eyes of the media. Especially when they had another alternative (S-600) all packed up and ready-to-go.

Being early in its lifecycle, Octa yields may not have been high enough to cover 80MM SGS4's expected to be sold this year and even if it was close Samsung might not have wanted to take a chance on supply shortages. And what the yields were going to be may not have been identified until late in the process which could explain the lack of h/w detail provided at the launch event and coding for multiple eventualities in the kernel.

According to iSuppli, Octa's more expensive than S-600 and Samsung Electronics may not have wanted to pay the premium to Samsung Semiconductor especially with the added development and support costs of maintaining a slew of different baseband interfaces.

As referenced above, Qualcomm's RF360 baseband should be in production this summer which lets a single baseband work across all 40 global LTE bands allowing for the first time LTE “roaming.” That means that Samsung only has to code a single interface between Octa and the baseband. Assuming it's released on schedule (summer), I expect it to be introduced in the N3 (fall) which would then be Octa/LTE everywhere it's sold in spite of the S-800 rumors we've heard. The introduction of RF360 is going to give all the mobile device manufacturers a lot more option on which SoC's they choose and assuming they are price/performance competitive there's no reason for Samsung Electronics not to use Samsung Semiconductor parts as the profit the latter's making on the sales flows up to the parent company's financials. If RF360's delayed I'd expect the N3 to end up Qualcomm/LTE - Octa/HSPA just like the SGS4.

Of all the things Samsung took in to consideration in deciding between Octa and S-600 for the SGS4 I don't think performance was even a consideration. Both the i9500 and i9505 are similar enough and so far ahead of the SGS3 that any performance differences (positive or negative) weren't substantial enough to matter. Decisions about an SoC for companies the size of Samsung aren't emotional and 10%+/- on battery life or benchmarks aren't meaningful enough to make spending more for such little gain to even matter. We on XDA care; the masses are clueless and take what they're given. I do think that with big.LITTLE being the next-generation of SoC they saw upside in getting it out and working with it early. Assuming it delivers the results originally promised (less energy used/more or similar power) the newer architecture it’s based on better maps to what OEM’s are looking for.

According to the ARM press release there will be seven big.LITTLE based devices released in the next six months. Let's see how they do before reaching any set conclusions. We're having a "checkers" discussion and big.LITTLE is all about "chess."